A study of filtering problems of background noise in nuclear spectrometry, improvement of signal-to-noise ratio, and of pulse characteristics produced by the optimum predictor device; Etude de problemes de filtrage de bruit de fond en spectrometrie nucleaire, amelioration du rapport signal sur bruit et des caracteristiques de l'impulsion mise en forme par le dispositif du predicteur optimum

Energy Technology Data Exchange (ETDEWEB)

Benda, J [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1967-05-01

The purpose of nuclear spectrometry is the precise measurement of particles energy. The resolving power of a spectrometer design is an important factor. Two main phenomena are involved in the limitation of this resolving power: The statistical fluctuations of the detector itself, and the background noise. For a given noise, the theory of filters enables the calculation of networks specially designed for the improvement of signal to noise ratio. The proposed system should lead to an improvement of 10.5 per cent of this ratio. Experiments have confirmed this theoretical estimation. The predictor device also makes possible the obtaining of shortened pulses. (author) [French] Les mesures en spectrometrie nucleaire ont pour but la determination precise de l'energie des particules. Le pouvoir de resolution d'une chaine de spectrometrie est une caracteristique importante. Deux phenomenes principaux concourent a limiter ce pouvoir de resolution: les fluctuations statistiques du detecteur et le bruit de fond. Pour un bruit de fond donne, la theorie des filtres permet de calculer des reseaux susceptibles de modifier le rapport signal sur bruit. Le systeme propose permet d'ameliorer de 10.5 pour cent ce rapport lorsqu'on se place dans les conditions optimales. Les resultats experimentaux confirment les previsions. Le dispositif predicteur permet aussi un raccourcissement de l'impulsion dans le temps. (auteur)

Rapport fra PES

DEFF Research Database (Denmark)

Austring, Bennyé D.; Sørensen, Merete

2011-01-01

Rapport fra PES konferencen på Høgskolen i Vestfolden, Larvik, Norge, der blev afholdt 4. og 5.5.2011- skrevet sammen med Merete Sørensen, Pædagoguddannelsen i Roskilde......Rapport fra PES konferencen på Høgskolen i Vestfolden, Larvik, Norge, der blev afholdt 4. og 5.5.2011- skrevet sammen med Merete Sørensen, Pædagoguddannelsen i Roskilde...

Statistical treatment of data. Application to nuclear electronics; Traitement des informations en regime statistique. Applications a l'electronique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Sicard, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

In this report the data of probability calculations are applied to the analyses of counting losses in experiments on chance events encountered in nuclear physics. The distribution of time intervals according to Poisson's law is studied and various applications of this are given: calculation of counting losses on a scale preceded by a fast de-multiplying circuit, decrease of the counting rate on the multichannel selectors, recording of statistical distribution phenomena on magnetic bands. (author) [French] Ce rapport applique les donnees du calcul des probabilites a l'analyse des pertes de comptage dans les experiences sur des evenements aleatoires rencontres en physique nucleaire. La distribution des intervalles de temps suivant une loi de Poisson est etudiee et differentes applications en sont donnees: calcul des pertes de comptage sur une echelle precedee d'un circuit de demultiplication rapide, diminution du taux de comptage sur les selecteurs multicanaux, enregistrement de phenomenes a distribution statistique sur bandes magnetiques. (auteur)

Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

Englander, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-11-15

In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

Rapport fra hovedudvalget

DEFF Research Database (Denmark)

Danmarks Miljøundersøgelser (bidragyder): Bichel-udvalget

Bicheludvalget, Udvalget til vurdering af de samlede konsekvenser af en hel eller delvis afvikling af pesticidanvendelsen. Rapporten er Bicheludvalgets endelige rapport til Miljø- og Energiministeren og bygger på 5 faglige baggrundsrapporter.......Bicheludvalget, Udvalget til vurdering af de samlede konsekvenser af en hel eller delvis afvikling af pesticidanvendelsen. Rapporten er Bicheludvalgets endelige rapport til Miljø- og Energiministeren og bygger på 5 faglige baggrundsrapporter....

Professional Nuclear Materials Management; Gestion Industrielle des Matieres Nucleaires; Obrashchenie s yadernymi materialami na professional'nom urovne; Administracion Eficiente de Materiales Nucleares

Energy Technology Data Exchange (ETDEWEB)

Forcella, A. A.; O' Leary, W. J. [Allis-Chalmers Manufacturing Company, Bethesda, MD (United States)

1966-02-15

. (author) [French] Le memoire expose en quoi consiste la gestion des matieres nucleaires dans une centrale nucleaire type, aux Etats-Unis. Comme le reacteur en question est partiellement finance a l'aide de capitaux prives, l'une des principales obligations de l'exploitant est d'assurer la protection et la rentabilite des investissements. Etant donne que les matieres nucleaires sont d'une valeur intrinseque elevee, il faut constamment proceder a des controles appropries allant au-dela des mesures de securite et de la comptabilite interessant les matieresnucleaires proprement dites afin de reduire les pertes au minimum. Il faut faire preuve de clairvoyance et planifier judicieusement pour prevenir toute perte supplementaire de capital provenant de frais inutiles ou d'un manque a gagner dans divers secteurs de l'exploitation. C'est ainsi que le gestionnaire de matieres nucleaires doit prendre des dispositions pour garantir la bonne marche des operations et assurer le respect des plans d'execution par une liaison et un controle constants, dans les domaines suivants? a) acquisition du combustible et des elements combustibles, b) utilisation des elements combustibles dans le reacteur et c) recuperation, dans le combustible irradie, des produits et matieres presentant de l'interet. Pendant la periode qui precede l'utilisation du reacteur, il faut faire une place importante dans la planification et les travaux preparatoires aux considerations d'economie dans la conception des elements combustibles, en ce qui concerne leur fabrication, leur manutention, leur transport et leur remplacement. Les differentes etapes de la fabrication doivent etre planifiees de facon a reduire au minimum le manque a gagner du a des periodes improductives d'entreposage de matieres tres couteuses. Pendant la marche du reacteur, il faut assurer une combustion maximale de la matiere fissile par des redistributions appropriees du combustible dans le coeur du reacteur. Parallelement, les temps morts dus a

Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

Energy Technology Data Exchange (ETDEWEB)

McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

1966-02-15

is of secondary importance and the cooling time is unimportant. Also, there is more precise nuclear data for the stable fission products. Of the stable isotopes produced during the fission process, zirconium, molybdenum, ruthenium, and neodymium appear to be the most useful. The proposed non-destructive methods using stable isotopes will be discussed. (author) [French] Il est a la fois utile et souhaitable d'utiliser des methodes non destructives pour proceder a la mesure quantitative du taux de combustion des elements combustibles d'un reacteur nucleaire. L'ideal serait de pouvoir analyser le combustible a l'aide d'une methode ne necessitant pas de renseignements particuliers sur les spectres des neutrons, le schema d'irradiation ou le temps de refroidissement. Les isotopes radioactifs et les isotopes stables resultant du processus de fission qui sont presents dans un element combustible irradie caracterisent son irradiation. Malheureusement, que l'analyse soit effectuee au moyen de methodes destructives ou non destructives, les resultats obtenus varient en fonction du spectre de neutrons, du schema d'irradiation et du temps de refroidissement. Deplus, l'absence de donnees nucleaires precises, comme les valeurs des section efficaces, influe sur tous les calculs qui peuvent etre effectues. L'analyse non destructive est egalement genee par la presence de champs de rayonnements intenses qui augmentent le bruit de fond. Il est difficile d'etablir des normes utiles et realistes. Bien que, dans l'etat actuel de la technique, les methodes non destructives n'aient pas toute la precision et l'exactitude voulues, elles presentent neanmoins un grand interet' notamment dans les cas ou il faut obtenir rapidement et economiquement une valeur approximative du taux de combustion. Plusieurs methodes non destructives d'evaluation du taux de combustion sont actuellement appliquees, a l'etude ou en projet. Plusieurs types de spectrometres sont utilises pour la mesure du rayonnement

Non-Destructive Testing of Plutonium-Enriched Fuel Rods; Controles non Destructifs de Barreaux Combustibles Enrichis au Plutonium; Nedestruktivnyj-kontrol' toplivnykh sterzhnej''obogashchennykh plutoniem; Ensayo no Destructivo de Elementos Combustibles Enriquecidos en Plutonio

Energy Technology Data Exchange (ETDEWEB)

Libotte, P.; Inniger, H.; Leblanc, J. M. [Centre D' Etude de l' Energie Nucleaire, Societe Belge pour l' Industrie Nucleaire, S.A. (Belgonucleaire), Mol (Belgium)

1965-09-15

ultrasonically by the pulse-echo technique. The respective advantages of the various non-destructive techniques are studied in relation to the required accuracy and to their possible application to the automated inspection of plutonium fuel rods fabricated on an industrial scale. (author) [French] La Societe belge pour l'industrie nucleaire (BelgoNucleaire) et le Centre d'etude de l'energie nucleaire (CEN) etudient sous contrat, en cooperation avec la Commission de l'EURATOM, l'utilisation du plutonium dans les reacteurs de puissance a eau pressurisee. Dans le cadre des recherches entreprises, differentes techniques de controle non destructif ont ete mises au point en vue d'evaluer la qualite des barreaux combustibles fabriques. Les essais non destructifs mis au point et decrits dans le memoire sont utilises essentiellement pour le controle des dimensions et de la qualite des tubes de gainage, de l'integrite des soudures, de l'etancheite des barreaux, de la densite du materiau combustible et de sa repartition, de l'enrichissement en plutonium et de sa distribution radiale et axiale dans le barreau combustible. Les methodes utilisees pour ces essais non destructifs comportent principalement les examens par radiographie, par autoradiographie, par gammagraphie et par les ultrasons. Le document reprend le principe de chacune des mesures realisees, et decrit dans chaque cas l'appareillage utilise et les techniques operatoires appliquees en vue d'obtenir les sensibilites et precisions desirees. La technique utilisee pour la radiographie permet de deceler des defauts de l'ordre de 50 a 60 {mu}m dans les soudures d'extremite des barreaux combustibles. Les combustibles etant densifies par vibration de trois fractions de poudre dense, dont la fraction fine seule comporte l'enrichissement en plutonium, il est essentiel que la repartition de ce dernier, de meme que la distribution de la densite, soient relevees avec precision. Le comptage du rayonnement gamma emergent emis par le plutonium

Contribution to the study of nuclear fuel materials with a metallic uranium base; Contribution a l'etude des materiaux combustibles nucleaires a base d'uranium metallique

Energy Technology Data Exchange (ETDEWEB)

Englander, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-11-15

In a power reactor destined to supply industrially recoverable thermal energy, the most economical source of heat still consists of natural metallic uranium. However, the nuclear fuel material, most often employed in the form of rods of 20 to 40 mm diameter, is subjected to a series of stresses which lead to irreversible distortions usually incompatible with the substructure of the reactor. As a result the fuel material must possess at the outset a certain number of qualities which must be determined. Investigations have therefore been carried out, first on the technological characters peculiar to each of the three allotropic phases of pure uranium metal, and on their interactions on the stabilisation of the material which consists of either cast uranium or uranium pile-treated in the {gamma} phase. (author) [French] Dans un reacteur de puissance destine a fournir de l'energie thermique industriellement recuperable, la source de chaleur la plus economique reste constituee par de l'uranium metallique naturel. Or, le materiau combustible nucleaire, employe le plus souvent sous forme de barreaux de 20 a 40 mm de diametre, se trouve soumis a un ensemble de contraintes qui provoque des deformations irreversibles, le plus souvent incompatibles avec l'infrastructure du reacteur. Par consequent, le materiau combustible doit presenter a l'origine un certain nombre de qualites qu'il est necessaire de determiner. Aussi a-t-on d'abord etudie les caracteres technologiques propres a chacune des trois phases allotropiques de l'uranium-metal pur et leurs interactions sur la stabilisation du materiau constitue soit par de l'uranium coule, soit par de l'uranium traite en pile en phase {gamma}. (auteur)

Integreret rapportering i praksis

DEFF Research Database (Denmark)

Pontoppidan, Caroline Aggestam; Sonnerfeldt, Amanda

2017-01-01

Formålet med denne artikel er at bidrage til en dybere forståelse af fænomenet integreret rapporte-ring () og, hvordan IIRC’s begrebsramme afspejles i praksis i virksomheder og af interessen-ter. Artiklen tager udgangspunkt i nyere empiriske forskningsprojekter, som bringer viden omkring......; 1) brugeres (stakeholders) informationsbehov, herunder anvendelsen og nytteværdien af og 2) praktiske udfordringer samt ’best practice’ tendenser inden for (ACCA, 2016; ACCA 2017; AcE, 2017; IFAC 2017)....

The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay; Formation des scientifiques et des techniciens au Centre d'Etudes Nucleaires de Saclay

Energy Technology Data Exchange (ETDEWEB)

Debiesse, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' waeated (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author)Fren. [French] Les besoins considerables actuels et previsibles en chercheurs et scientifiques necessites par l'avevement de l'energie nucleaire imposaient au Commissariat a I'Energie atomique un effort particulier pour augmenter la formation quantitative et qualitative des scientifiques. Les moyens les plus divers ont ete mis en oeuvre: 1- Creation de l'Institut National des Sciences et Techniques Nucleaires par decret de la Presidence du Conseil et de l'Education Nationale en date du 18.6.57. Cet Institut d'Enseignement Superieur (250 etudiants) donne des cours en: genie atomique, mecanique quantique, theorie et technique des Accelerateurs de particules, metallurgie speciale, radiobiologie

The nuclear power stations of the French atomic energy programme (1960); Les centrales nucleaires de puissance du programme francais (1960)

Energy Technology Data Exchange (ETDEWEB)

Leduc, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Roux, J P [Electricite de France (EDF), 75 - Paris (France)

1960-07-01

After recalling the entry of nuclear energy into energy production in France, the paper emphasizes the evolution of techniques applied in the designing of French nuclear power plants and describes the means employed for reducing costs per kWh of EDF2 and EDF3 compared with EDF1: the electric power per ton of uranium varies from 493 kW/t for EDF1 to 970 kW/t for EDF3. For this purpose the thermal power and electric power of units are changed respectively from 290 MWt for EDF1 to 1200 or 1600 MWt for EDF3 and from 28 to 250 MW. The results are obtained by an improvement in neutronic characteristics, developments in nuclear fuel technology, and simplification of the system of charging the reactor, whose means of maintenance are increased; the EDF2 heat-exchangers have been so designed as to increase the unit power of the elements, which will attain 9 MWt, as against 3 for EDF1. For EDF3 an advance project forecasts a thermodynamic layout with only one pressure stage. The paper ends with a description of the burst-slug detection systems, and an appendix gives a detailed comparative table of EDF1, EDF2 and EDF3 plant characteristics. (author) [French] Apres avoir rappele l'integration de l'energie nucleaire parmi les moyens de production de l'energie en France, les auteurs se penchent surtout sur l'evolution des techniques appliquees dans l'equipement des centrales nucleaires francaises et decrivent les moyens mis en oeuvre pour reduire les prix de revient du kWh d'EDF2 et d'EDF3 par rapport a EDF1: la puissance electrique par tonne d'uranium varie de 493 kW/t pour EDF1 a 970 kW/t pour EDF3. C'est dans ce but que les puissances thermiques et la puissance unitaire des groupes turbo-alternateurs passent respectivement de 290 MWt pour EDF1 a 1200 ou 1600 MWt pour EDF3 et de 82 a 250 MW. Les resultats sont obtenus par une amelioration des caracteristiques neutroniques, des progres realises sur la technologie des elements combustibles, une simplification du systeme de

Functioneel Ontwerp Integratie BMNI/LMR

NARCIS (Netherlands)

LSO

1995-01-01

In dit rapport wordt de meetnetconfiguratie van het Nationaal Meetnet Radioactiviteit (NMR) gepresenteerd. Het NMR zal opgebouwd worden uit de bestaande meetnetten van de Rampenbestrijdingsorganisatie van Binnenlandse Zaken, het Binnenlandse Zaken Meetnet Nucleaire Incidenten (BMNI), en van

French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Guerin De Montgareuil, P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

). Le dossier des techniques nucleaires est surtout represente par les radioisotopes (carbone 14, phosphore 32, soufre 35, calcium 45, potassium 42, cuivre 64, or 198) et les isotopes stables analyses au spectrometre de masse (azote 15, oxygene 18) ou par activation aux neutrons (bore 10). Les travaux mentionnes se rapportent a des questions de niveau tres variable en physiologie vegetale, agrologie, entomologie agricole et zootechnie. On cite egalement les resultats obtenus a propos des mesures de l'humidite (thermalisation neutronique) et de la densite (diffusion gamma) d'un sol. A ces differentes recherches prennent part, chacun selon sa vocation propre, de nombreux organismes: entreprise privee a caractere cooperatif, firmes industrielles, laboratoires universitaires, instituts scientifiques. A cette occasion, se trouve precise le role du Commissariat a l'Energie Atomique: d'une part, information et soutien, d'autre part, prise en charge des aspects specifiquement nucleaires. Son intervention dans ce domaine s'est recemment traduite par la creation, au sein du Departement de Biologie, d'une Section de Radioagronomie dont on decrit les objectifs ainsi que les moyens mis a sa disposition au Centre d'Etudes Nucleaires de Cadarache. (auteur)

Rapport annuel au Parlement Loi sur la protection des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Larocque, Samia

1 juil. 1983 ... TBS/SCT 350-63 (Rév. 2011/03). 31/03/2014. 01/04/2013. Période visée par le rapport : Reçues pendant la période visée par le rapport. Total. En suspens à la fin de la période de rapport précédente. Rapport statistique sur la Loi sur la protection des renseignements personnels. Nom de l'institution :.

Instructor-Student Rapport in Taiwan ESL Classrooms

Directory of Open Access Journals (Sweden)

Nathan G. Webb

2014-09-01

Full Text Available Positive relationships between instructors and students are critical to effective learning in the classroom. Rooted in the Scholarship of Teaching and Learning (SoTL, and centered at the crossroads of interpersonal communication and instructional communication (Affective Learning Model, this study examines how instructors in a Taiwan ESL school build relationships with Taiwanese students. Instructors were interviewed regarding the behaviors they use to build rapport with their students. Results show that instructors build rapport with their students using several specific techniques: uncommonly attentive behaviors, common grounding behaviors, courteous behaviors, connecting behavior, information sharing behavior, a balancing of connection and authority, adaptation of rapport to student level, and provision of a respite to norms. The findings provide specific examples of how instructors can build rapport in intercultural classrooms.

Rapport om digitale oplysninger ved Aalborg Universitet

DEFF Research Database (Denmark)

Bønsing, Sten

Rapport til Aalborg Universitets ledelse vedr. brug af digitale oplysninger i forbindelse med e-mailing, databaser, hjemmesider mv.......Rapport til Aalborg Universitets ledelse vedr. brug af digitale oplysninger i forbindelse med e-mailing, databaser, hjemmesider mv....

G2 - G3 inventive properties, the first french nuclear plants; Caracteristiques generales et aspects originaux des reacteurs G2 et G3

Energy Technology Data Exchange (ETDEWEB)

Pascal,; Horowitz,; Bussac,; Joatton,; de Meux, De Lagge; Martin, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

This paper points out the inventive properties of the frenchctors G2 and G3. These are dual purpose reactors, i.e. designed for the production of both plutonium and energy (30 electrical MW); in this respect, they can be considered as the start point of the french electrical energy produced from nuclear fuel. The following points are specially discussed in this paper: the choice of the prestressed concrete pressure vessel, the horizontal arrangement of the channels, the interest of neutron flux flattening, the advantages of the charging and discharging device working during pile operation. (author)Fren. [French] Les caracteres originaux des reacteurs fran is G2 et G3 sont decrits dans ce rapport. Ce sont des reacteurs a double fin, plutonigenes et aussi producteurs d'energie (30 MW electriques); ils constituent a ce titre le point de depart de la production fran ise d'electricite d'origine nucleaire. Sont discutes, en particulier, dans ce rapport: le choix du caisson en beton precontraint pour tenir la pression, la disposition horizontale des canaux, l'interet de l'aplatissement du flux neutronique, les avantages de l'appareil permettant le chargement et le dechargement du combustible sans arreter la pile. (auteur)

Reducing negative affect and increasing rapport improve interracial mentorship outcomes.

Science.gov (United States)

Leitner, Jordan B; Ayduk, Özlem; Boykin, C Malik; Mendoza-Denton, Rodolfo

2018-01-01

Research suggests that interracial mentoring relationships are strained by negative affect and low rapport. As such, it stands to reason that strategies that decrease negative affect and increase rapport should improve these relationships. However, previous research has not tested this possibility. In video-chats (Studies 1 and 2) and face-to-face meetings (Study 3), we manipulated the degree of mutual self-disclosure between mentees and mentors, a strategy that has been shown to reduce negative affect and increase rapport. We then measured negative affect and rapport as mediators, and mentee performance (quality of speech delivered; Studies 1 and 3) and mentor performance (warmth and helpfulness; Studies 2 and 3) as key outcomes. Results revealed that increased self-disclosure decreased negative affect and increased rapport for both mentees and mentors. Among mentees, decreased negative affect predicted better performance (Studies 1 and 3). Among mentors, increased rapport predicted warmer feedback (Studies 2 and 3). These effects remained significant when we meta-analyzed data across studies (Study 4), and also revealed the relationship of rapport to more helpful feedback. Findings suggest that affect and rapport are key features in facilitating positive outcomes in interracial mentoring relationships.

Optimal sizes and siting of nuclear fuel reprocessing plants; Tailles et localisations optimales des usines de retraitement des combustibles nucleaires

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Deledicq, A [Commissariat a l' Energie Atomique, Siege (France). Centre d' Etudes Nucleaires

1967-07-01

The expansion of a nuclear economy entails the development of fuel process and reprocessing plant programmes. The model proposed makes it possible to select the size, the site and the start-up schedule of the plants in such a way as to minimize the total freight and reprocessing costs. As an illustration, we have approached the problem of burnt natural uranium processing plants related to natural uranium-graphite as nuclear power stations. The sites and annual output of the reactors, the possible plant sites and cost functions (freight and reprocessing) are supposed to be known. The method consists in first approaching the process plant problem as a Dynamic Programming problem, increasing programme slices (total reactor output) being explored sequentially. When the quantities of burnt natural uranium to be reprocessed are fixed, the minimization of the transport cost is then also carried out as a dynamic programming problem. The neighbourhood of the optimum process cost is explored in order to find the minimum summation of a suboptimal processing cost and corresponding optimal transport cost. As the reprocessing problem can be represented on a sequential graph, in order to compute the sub-optima, we developed and used a 'reflexion algorithm'. The method can be interpreted as a general mechanism for determining the optimum when to a sequential dynamic problem (for example an equipment programme) is added a complementary problem (transport, for instance). It also makes it possible to estimate the economic losses which result from the choice of a non optimal policy for other than economic reasons. (author) [French] L'expansion de l'economie nucleaire se traduit par un developpement des programmes d'usines d'elaboration et de retraitement des combustibles. Le modele propose permet de choisir la taille, la localisation et la cadence de mise en service des usines de maniere a minimiser le total des frais de transport et de retraitement. A titre d'exemple nous avons

Rapports annuels | CRDI - Centre de recherches pour le ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapports annuels. Le CRDI publie un rapport annuel dans lequel il présente ses états financiers et ses résultats. Ce rapport met en outre en évidence des chercheurs bénéficiaires de subventions du CRDI et en décrit les projets et les réalisations clés. C'est le principal outil par lequel le Centre rend compte de ses activités ...

Factors and uncertainties in the profitability of using nuclear energy in desalination of water; Facteurs et incertitudes de la rentabilite du recours a l'energie nucleaire dans le dessalement des eaux

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Lievre, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

One of the economic advantages of nuclear energy consists of the small proportional element in its cost structure. Economies of scale favour the nuclear station as compared with the conventional thermal one, and when the demand for electricity and heat, in particular for desalination, are sufficient, nuclear energy may, subject to certain conditions, prove advantageous. The object of this paper is to discuss the validity of the conclusions reached according to the hypotheses adopted. In the first part, the different kind of uncertainties connected with technical, economic and financial data (the various transmission coefficients, the life of equipment according to the choice of materials, changes in prices, the form of price functions and interest rates), and with the various constraints, are examined and discussed. In the second part the uncertainties connected with the method of optimisation used and the criterion of selection adopted are examined and discussed. It is shown thereby that it is usually extremely difficult to assume absolutely the competitiveness, or conversely the non-competitiveness, of using nuclear energy in the desalination of water, and that a large number of aspects have to be carefully examined. (author) [French] On sait que l'un des avantages economiques de l'energie nucleaire reside dans la faible part proportionnelle dans la structure de son cout. Les economies d'echelle favorisent le nucleaire par rapport au thermique classique, et lorsque les demandes d'electricite et de chaleur, notamment pour le dessalement, sont suffisantes on peut envisager favorablement, sous certaines hypotheses, le recours a l'energie nucleaire. L'objet de cette communication est de discuter la validite des conclusions auxquelles on parvient selon les hypotheses envisagees. Dans une premiere partie, on etudie et on discute les differentes sortes d'incertitudes, liees aux donnees techniques, economiques et financieres (les divers coefficients de transmission, les

Evolution of nuclear chemical industry in France; Evolution de l'industrie chimique nucleaire en France

Energy Technology Data Exchange (ETDEWEB)

Fould, M H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

'impulsion du CEA, mais aussi de maitres d'oeuvres tels qu'Electricite de France et la Marine Marchande, l'effort nucleaire fran is atteint pour les annees 1957-1961, environ 600 milliards de francs: plus de la moitie de cette somme sera depensee par l'industrie chimique en recherches, installations pilotes, constructions d'usines et livraisons. Faire bien, vite et rentable sont les buts recherches. Ces objectifs sont atteints grace a une collaboration intime des grands services de l'etat et de l'industrie privee. Ce gros effort s'exerce principalement dans les voies suivantes: - Un traitement chimique pousse de tonnages croissants des minerais de l'Union fran ise, visant a produire un uranium pur, abondant et bon marche. - Une preparation soigneuse de combustibles nucleaires economiques et parfaitement adaptes aux divers types de reacteurs en fonctionnement ou en construction. - Un retraitement des combustibles irradies pour en extraire le plutonium de facon complete ainsi que l'uranium et certains produits de fission. - Une fabrication industrielle des materiaux nucleairement purs ou resistants a la corrosion exiges par la technologie des reacteurs producteurs d'energie et de recherches. - La fourniture aux multiples utilisateurs etrangers et fran is d'isotopes et de traceurs radioactifs reclames par la medecine, l'industrie et l'agriculture en nombre toujours croissant. - Un traitement chimique meticuleux des effluents gazeux ou liquides dans des stations au controle rigoureux afin de rendre les reacteurs et leurs annexes parfaitement surs d'emploi. Cet expose aura montre l'ampleur de l'effort deploye par une industrie chimique nucleaire jeune, dynamique et en plein essor. Ayant assure ses techniques, realise de nombreuses installations, elle est largement en etat de faire face au programme atomique fran is. En outre, elle est capable et desireuse d'etre associee aux developpements de l'industrie atomique etrangere notamment dans te cadre de l'Euratom et d

French research in the field of nuclear agronomy; Les recherches francaises en agronomie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Guerin De Montgareuil, P. [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1964-07-01

'amidon, metabolisme glucidique des tubercules irradies, radioresistance des levures). Le dossier des techniques nucleaires est surtout represente par les radioisotopes (carbone 14, phosphore 32, soufre 35, calcium 45, potassium 42, cuivre 64, or 198) et les isotopes stables analyses au spectrometre de masse (azote 15, oxygene 18) ou par activation aux neutrons (bore 10). Les travaux mentionnes se rapportent a des questions de niveau tres variable en physiologie vegetale, agrologie, entomologie agricole et zootechnie. On cite egalement les resultats obtenus a propos des mesures de l'humidite (thermalisation neutronique) et de la densite (diffusion gamma) d'un sol. A ces differentes recherches prennent part, chacun selon sa vocation propre, de nombreux organismes: entreprise privee a caractere cooperatif, firmes industrielles, laboratoires universitaires, instituts scientifiques. A cette occasion, se trouve precise le role du Commissariat a l'Energie Atomique: d'une part, information et soutien, d'autre part, prise en charge des aspects specifiquement nucleaires. Son intervention dans ce domaine s'est recemment traduite par la creation, au sein du Departement de Biologie, d'une Section de Radioagronomie dont on decrit les objectifs ainsi que les moyens mis a sa disposition au Centre d'Etudes Nucleaires de Cadarache. (auteur)

Bepaling van 14C in afvalwater

NARCIS (Netherlands)

Hiemstra YS; Kwakman PJM; Nissan LN; Aldenkamp FJ; LSO

1998-01-01

In opdracht van de Hoofdinspectie Milieuhygiene van het ministerie van VROM heeft LSO een methode ontwikkeld om 14C in afvalwater van nucleaire installaties te bepalen. De methode meet organisch gebonden-14C en anorganisch-14C in de vorm van carbonaat (14CO32-) in afvalwater. Het rapport

Ny rapport advarer

DEFF Research Database (Denmark)

Jex, Catherine; Seidenkrantz, Marit-Solveig; Colgan, William

2017-01-01

Ifølge forskerne bag en ny mellemstatslig rapport vil den globale opvarmning få endnu flere og meget drastiske konsekvenser for det arktiske klima end hidtil antaget. Men klimaaftalen fra Paris kan afværge nogle af de største forandringer efter år 2050. Hvis den bliver implementeret øjeblikkeligt...

Treatment of Radioactive Effluents at the Saclay Nuclear Research Centre; Traitement des Effluents Radioactifs au Centre d'Etudes Nucleaires de Saclay; 041e 0414 ; Tratamiento de los Efluentes Radiactivos en el Centro de Energia Nuclear de Saclay

Energy Technology Data Exchange (ETDEWEB)

Wormser, G. [Service de Controle des Radiations et de Genie Radioactif, Commissariat a l' Energie Atomique, Saclay (France)

1960-07-01

The Report Gives The Account Of Four Years' Experience In Operating The Treatment Plant For Effluents From The Saclay Nuclear Research Centre. It Contains Data Relating To The Origin, Volume And Treatment Of Waste. (author) [French] Ce rapport presente un bilan d'exploitation de l'installation de traitement des effluents du Centre d'etudes nucleaires de Saclay depuis quatre ans. On donne des chiffres concernant l'origine des residus, leur volume, leur traitement. (author) [Spanish] El autor hace un balance de explotacion de la instalacion de tratamiento de efluentes del centro de Saclay desde hace cuatro anos, dando las cifras correspondientes al origen de los residuos, a su volumen y a su tratamiento. (author) [Russian] V jetom dokumente podvoditsja itog chetyrehletnej jekspluatacii ustanovki po obrabotke zhidkih othotov v Centre jadernyh issledovanij v Sakle. V doklade privodjatsja dannye o proishozhdenii othodov, jh ob'eme i obrabotke. (author)

Strategies in Managing Rapport in Classroom Discussion

OpenAIRE

Reski Reski

2018-01-01

This paper aims to find out the strategies, applied by students in classroom interaction particularly in discussion, to maintain their interpersonal rapport as well as to enhance their rapport management with their fellow students. There are five strategies based on Spencer-Oatey (2008) that the interactants apply in social interactions. The strategies are request, compliments, apologies, gratitude and disagreement. The research is done to see whether the students realize the management of ra...

Rapport 7204

DEFF Research Database (Denmark)

Rathkjen, Arne

1972-01-01

I denne rapport redegøres for en serie forsøg med træbjælker med I-tværsnit. Forsøgene er rekvireret af og bjælkerne leveret af Hirtshals Savværk i forbindelse med et projekt udført af Søren Abrahamsen og H. P. Nielsen, rådg. ingeniører. Forsøgene havde til formål at give oplysninger om bjælkernes...

Siloette, Siloe mock-up; Siloette, modele nucleaire de siloe

Energy Technology Data Exchange (ETDEWEB)

Delcroix, V; Jeanne, G; Mitault, G; Schulhof, P [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

Siloette is the Siloe mock-up. The main installations are described: various tanks, building, auxiliaries, control systems... Precis ions are given about precautions taken for using spent fuel elements. (authors) [French] Siloette est le modele nucleaire de SILOE. On decrit ses diverses installations: bassins, batiments, auxiliaires, controle... Des precisions sont donnees sur les precautions prises pour y utiliser des elements uses. (auteurs)

(ReExamining the Feminist Interview: Rapport, Gender “Matching,” and Emotional Labour

Directory of Open Access Journals (Sweden)

Rachel Thwaites

2017-11-01

Full Text Available Rapport is usually considered key to any interview situation: building the right kind of rapport can be the difference between success and failure in obtaining the required data. In feminist research, rapport is intended to be of a particular kind: created through mutual sharing, minimal power hierarchies, and a feeling of genuine trust between interviewer and interviewee (Oakley, 1981. There is a tension here of which feminist researchers and scholars should remain critical, as the idea of good feminist rapport can clash with the necessity of “getting the data.” Building rapport can entail minimising strongly held viewpoints, working hard on one’s emotions to ensure they do not reveal true thoughts, or suggesting an attitude of trust and mutual understanding that may feel disingenuous. If rapport is often a performance by the researcher, then this can clash with the intended open and honest feminist approach. In some cases, then, building rapport may pose a challenge to genuinely following a feminist approach to the research interview. In this paper, I wish to explore this tension in more detail in the context of the one-off interview and to what extent it can be resolved.

Associative memories in nuclear physics; Les memoires associatives en physique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Blanca, E; Carriere, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

Experiments in nuclear physics involve the use of large size 'memories'. After showing the difficulties arising from the use of such memories, the authors give the principles of the various programming methods which make it possible to operate the memories associatively thus benefiting from a reduction in size and better operational conditions. They attempt to estimate the shape and dimensions of an associative memory with cable connections which could be designed specially for nuclear research, contrary to those actually in service. (authors) [French] Les experiences de physique nucleaire necessitent l'emploi de 'memoires' de grandes dimensions. Apres avoir montre les inconvenients que presente l'utilisation de telles memoires, les auteurs exposent les principes des diverses methodes de programmation qui permettent d'assurer un fonctionnement des memoires sur le mode associatif donc une reduction de leurs dimensions et un meilleur usage. Ils tentent d'evaluer le format d'une memoire associative cablee qui, contrairement a celles qui existent actuellement, serait prevue specialement pour l'experimentation nucleaire. (auteurs)

CIDEA Rapport 2

DEFF Research Database (Denmark)

Scheele, Christian Elling

2011-01-01

I denne ”state of the art” rapport, der er udarbejdet som en del af CIDEA-projektet, fokuseres på internetapplikationer, der har til formål at motivere til adfærdsændringer på klimaområdet. Der er i denne sammenhæng tale om adfærdsændringer, som har til formål at få individer -individuelt såvel som...

Quantitative measurements of small isotopic samples in gaseous mixtures by utilization of some nuclear properties; Etude des possibilites de mesures de faibles quantites de gaz radioactifs dans un melange en utilisant simultanement plusieurs proprietes nucleaires

Energy Technology Data Exchange (ETDEWEB)

Maragnon, J; Delperie, C

1967-12-01

The question is to define the characteristics of a group of measurements allowing the analysis of traces of radioactive rare gases in gas mixtures of different composition. To distinguish the radioactive isotopes from each other and the activity level reaching 10{sup 6} due to their nuclear properties, the method was chosen to use several nuclear properties: gamma radiation energy, beta particle energy, lifetime of excited states. The choice of a plastic scintillator as beta detector allows to answer satisfactorilly to this demand by measurement of nuclear constants because of the short de/excitation time of this detector. Another advantage is that it can be a reservoir for the sample without any destruction nor modification of the sample. The study has been based on the mixture of Kr-85, the analysis of other rare gases follwos immediately from the adopted principle. [French] Les auteurs ont oriente leur recherche vers une solution permettant de distinguer les isotopes radioactifs les uns des autres et dans des rapports d'activite pouvant atteindre 10{sup 6}, grace a plusieurs de leurs proprietes nucleaires, energie de rayonnement gamma, energie de la particule beta, temps de vie des niveaux excites. Le choix d'un scintillateur plastique comme detecteur beta permet de repondre d'une maniere satisfaisante a la mesure des constantes nucleaires en raison du temps de de/excitation rapide de ce scintillateur. Il offre en outre l'avantage de pouvoir servir de reservoir a l'echantillon sans entrainer aucune destruction ni modification de celui-ci. L'etude a ete basee sur la mixture de Kr-85, l'analyse des autre gaz rares decoulant immediatement du principe adopte. (auteur)

Differential measurement of the earth's magnetic field by nuclear magnetic resonance; Mesure differentielle du champ magnetique terrestre par resonance magnetique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Robach, F [Commissariat a l' Energie Atomique, 38 - Grenoble (France). Centre d' Etudes Nucleaires

1967-07-01

MNR transducers using proton dynamic polarisation allows to convert into a phase measurement any variation of the earth magnetic field. There exist several versions of the instrument corresponding to various models of MNR transducers, which the author analyses in detail, devoting an important place to influence of their alignment with respect to the earth's magnetic field. The sensibility obtained is of one hundredth of a gamma over a bandwidth of (0-0,1 Hz). - This instrument is designed for measuring field gradients in airborne magnetic surveying, for detecting nearly magnetic anomalies, and for distinguishing between nearly and distant magnetic phenomena. (author) [French] L'emploi de capteurs, bases sur la resonance magnetique nucleaire des protons en presence de polarisation dynamique, permet de traduire une difference de champ magnetique terrestre en une mesure de phase. L'appareil existe sous plusieurs versions avec des capteurs de modeles differents dont l'auteur fait une analyse detaillee en accordant une part importante a l'influence de l'orientation des capteurs par rapport au champ magnetique terrestre. La sensibilite est de 1/100 {gamma} pour une bande passante de (0 - 0,1 Hz). Cet appareil s'applique a la mesure du gradient en prospection magnetique aeroportee, a la detection d'anomalies magnetiques proches, a la differentiation d'effets magnetiques proches et lointains. (auteur)

Technique of nuclear reactors controls; Technique des controles des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Weill, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1953-12-15

This report deal about 'Techniques of control of the nuclear reactors' in the goal to achieve the control of natural uranium reactors and especially the one of Saclay. This work is mainly about the measurement into nuclear parameters and go further in the measurement of thermodynamic variables,etc... putting in relief the new features required on behalf of the detectors because of their use in the thermal neutrons flux. In the domain of nuclear measurement, we indicate the realizations and the results obtained with thermal neutron detectors and for the measurement of ionizations currents. We also treat the technical problem of the start-up of a reactor and of the reactivity measurement. We give the necessary details for the comprehension of all essential diagrams and plans put on, in particular, for the reactor of Saclay. (author) [French] Nous avons aborde le probleme de la ''Technique du Controle des reacteurs nucleaires'' dans le but de realiser le controle du reacteur de Saclay. C'est ainsi que nous avons ete amene a etudier le probleme dans son ensemble, tel qu'il se pose pour tout reacteur a uranium naturel. Ce travail traite principalement du domaine des mesures a caractere nucleaire et s'etend dans le domaine des mesures thermodynamque de niveaux, etc... mettant en relief les caracteristiques nouvelles exigees de la part des detecteurs du fait de leur utilisation dans le flux de neutrons thermiques. Dans le domaine de mesures nucleaires, nous indiquons principalement les realisations et les resultats obtenus pour les detecteurs de neutrons thermiques et pour la mesure de courants d'ionisations. Nous traitons egalement du probleme technique du demarrage d'un reacteur et du probleme de la mesure de la reactivite. Nous donnons les details necessaires a la comrehension de tous les schemas et plans de cablages essentiels mis au point, en particulier, pour le reacteur de Saclay. (auteur)

Current regulator for the stabilization of an electrostatic Van de Graaff generator; Regulateur de courant pour stabilisation d'un generateur electrostatique Van de Graaff

Energy Technology Data Exchange (ETDEWEB)

Gabet, A; Taieb, J [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1953-07-01

In a previous report (CEA report number 46) we described a current regulator destined to enslave the current of charge of the strap of a model of Van de Graaff. We will now describe the regulator destined to the 5 MeV Van de Graaff built in the Nuclear center of Saclay. (author) [French] Dans un precedent rapport (rapport C.E.A. numero 46) nous avons decrit un regulateur de courant destine a asservir le courant de charge de la courroie d'une maquette de Van de Graaff. Nous decrirons maintenant le regulateur destine au Van de Graaff de 5 MeV construit au Centre d'Etudes Nucleaires de Saclay. (auteur)

ØG-DDB teknisk rapport

DEFF Research Database (Denmark)

Vestergaard, Flemming; Karlshøj, Jan; Hauch, Peter

Nærværende rapport er den tekniske slutrapport for projektet Måling af økonomiske gevinster ved Det Digitale Byggeri (byggeriets digitalisering). Projektet er finansieret af Klima-, Energi og Bygningsstyrelsen og har haft en projektperiode fra medio 2009 til primo 2012. Projektet er udført på DTU...

Revenge versus rapport: Interrogation, terrorism, and torture.

Science.gov (United States)

Alison, Laurence; Alison, Emily

2017-04-01

This review begins with the historical context of harsh interrogation methods that have been used repeatedly since the Second World War. This is despite the legal, ethical and moral sanctions against them and the lack of evidence for their efficacy. Revenge-motivated interrogations (Carlsmith & Sood, 2009) regularly occur in high conflict, high uncertainty situations and where there is dehumanization of the enemy. These methods are diametrically opposed to the humanization process required for adopting rapport-based methods-for which there is an increasing corpus of studies evidencing their efficacy. We review this emerging field of study and show how rapport-based methods rely on building alliances and involve a specific set of interpersonal skills on the part of the interrogator. We conclude with 2 key propositions: (a) for psychologists to firmly maintain the Hippocratic Oath of "first do no harm," irrespective of perceived threat and uncertainty, and (b) for wider recognition of the empirical evidence that rapport-based approaches work and revenge tactics do not. Proposition (a) is directly in line with fundamental ethical principles of practice for anyone in a caring profession. Proposition (b) is based on the requirement for psychology to protect and promote human welfare and to base conclusions on objective evidence. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

Energy Technology Data Exchange (ETDEWEB)

Megemont, C; Grau, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-10-01

From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

Piles used for the nuclear control of materials; Empilements pour le controle nucleaire des materiaux

Energy Technology Data Exchange (ETDEWEB)

Raievski, V; Sautiez, B; Bailly du Bois, B; Tretiakoff, O; Thome, P; Vidal, R; Koppel Martelly, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The devices which make it possible to check on the nuclear qualities of the materials used in reactor construction are described. These verifications bear on substantial masses of materials, following the last stage of their machining. The components found in all these are a graphite pile into which the material to be investigated is inserted, a source of neutrons made up of an Ra-Be system, and a proportional BF{sub 3} counter. The devices described here bear on checking graphite, beryllium oxide and uranium absorption, as well as on a verification of the {sup 235}U content of fuel elements. (author)Fren. [French] On decrit des dispositifs permettant de controler les qualites nucleaires de materiaux utilises dans la construction des piles. Ce controle s'effectue sur des masses importantes de materiaux apres la phase finale d'usinage. Ces dispositifs ont en commun un empilement de graphite recevant le materiau a etudier, une source de neutrons de Ra-Be et un compteur proportionnel a BF{sub 3}. Les dispositifs decrits concernent le controle de l'absorption du graphite, de la glucine et de l'uranium, ainsi que le controle de la teneur en {sup 235}U des elements de combustion. (auteur)

Review of Development Status of Nuclear Superheat; Expose sur l'etat actuel des travaux concernant la surchauffe nucleaire; Obzor razrabotki voprosa o yadernykh peregrevatelyakh; Estudio de los progresos realizados en niateria de sobrecalentamiento nuclear

Energy Technology Data Exchange (ETDEWEB)

Imhoff, D. H.; Pennington, R. T. [General Electric Company, San Jose, CA (United States)

1963-10-15

fuel irradiation performance, in-pile and out-of-pile uniform and localized corrosion evaluations, results from thermal superheat critical experiments, results from experimental heat-transfer testing and a brief appraisal of the economic incentives of the separate superheat reactor, integral superheat reactor, and mixed-spectrum superheat reactor design studies. (b) A brief description is given of the USAEC-Sponsored ESADA-VESR nuclear superheat fuel development programme. The development tasks, the initial core superheat fuel-element design, the range of experimental variables, and the expected results for the three-year fuel development programme are discussed. (author [French] Depuis 1959, la Societe General Electric s'occupe activement de mettre au point la surchauffe nucleaire dans les reacteurs ralentis a l'eau ordinaire. A cette epoque, le ''Superheat Advance Demonstration Experiment'' (SADE), finance par la societe, a permis d'obtenir, pour la premiere fois aux Etats-Unis, de la vapeur surchauffee par un dispositif nucleaire. Les auteurs du memoire font le point de la situation actuelle concernant la surchauffe nucleaire. Ils decrivent, dans une premiere partie, les trois principales installations de surchauffe nucleaire utilisees par la General Electric et, dans la seconde, les deux principaux programmes de recherches sur la surchauffe ainsi que les resultats les plus importants obtenus jusqu'ici dans ce domaine. 1. Principales installations pour les experiences de surchauffe: a) Breve description du SADE utilise dans le reacteur a eau bouillante de Vallecitos (VBWR), avec tableaux des conditions dans lesquelles se deroulent les experiences, et des elements combustibles irradies pendant la periode comprise entre mai 1959 et juin 1962; puis examen critique des resultats les plus importants ainsi obtenus. b) Breve description de l' ''Expanded Superheat Advance Demonstration Experiment'' (E-SADE) installe dans le reacteur de Vallecitos, avec tableaux des

An absolute nuclear magnetic resonance magnetometer; Magnetometre absolu a resonance magnetique nucleaire

Energy Technology Data Exchange (ETDEWEB)

Salvi, A [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-10-15

After an introduction in which the various work undertaken since the discovery of nuclear magnetic resonance is rapidly reviewed, the author describes briefly In the first chapter three types of NMR magnetometers, giving the advantages and disadvantages of each of them and deducing from this the design of the apparatus having the greatest number of qualities Chapter II is devoted to the crossed coil nuclear oscillator which operates continuously over a wide range (800 gamma). To avoid an error due to a carrying over the frequency, the measurement is carried out using bands of 1000 {gamma}. Chapter III deals with frequency measurements. The author describes an original arrangement which makes possible the frequency-field conversion with an accuracy of {+-} 5 x 10{sup -6}, and the differential measurement between two nuclear oscillators. The report finishes with a conclusion and a few recordings. (author) [French] Apres une introduction rappelant les divers travaux effectues en resonance magnetique nucleaire depuis sa mise en evidence, l'auteur decrit sommairement dans le premier chapitre trois types de magnetometre a R.M.N. enumerant les avantages et les inconvenients de chacun a partir desquels il projet, l'appareillage reunissant le maximum de qualites. Le chapitre II est consacre a l'oscillateur nucleaire a bobines croisees permettant un fonctionnement continu dons une large plage (800 gamma). Pour eviter une erreur due a l'entrainement de frequence, la mesure s'effectue par bandes de 1000 {gamma} chacune. Le chapitre III traite la mesure de frequence. L'auteur expose un montage original permettant la traduction frequence-champ avec une precision egale a {+-} 5.10{sup -6}, et la mesure differentielle entre deux oscillateurs nucleaires. Une conclusion et quelques enregistrements terminent ce travail. (auteur)

Developing patient rapport, trust and therapeutic relationships.

Science.gov (United States)

Price, Bob

2017-08-09

Rapport is established at the first meeting between the patient and nurse, and is developed throughout the therapeutic relationship. However, challenges can arise during this process. Initially, nurses can establish trust with the patient through the questions they ask, however, as care progresses, the nurse will be required to demonstrate a commitment to maintaining the patient's psychological well-being. When the therapeutic relationship ends, the nurse should assist the patient to assess progress and plan the next stage of recovery. This article provides three reflective exercises using case study examples to demonstrate how rapport is developed and sustained. Evidence is provided to identify why challenges arise in the therapeutic relationship and how the nurse can ensure they provide care that the patient regards as genuine.

Contribution to the study of nuclear resonance in magnetic media (1963); Contribution a l'etude de la resonance nucleaire dans les milieux magnetique (1963)

Energy Technology Data Exchange (ETDEWEB)

Hartmann-Boutron, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-06-15

An attempt is made to interpret the results of nuclear magnetic resonance experiments made by various workers on ferro and ferrimagnetic compounds of the iron group. The problems encountered are the following: effects of the dipolar fields and the hyperfine structure anisotropy; signal intensity; frequency pulling due to the Suhl-Nakamura interaction between nuclear spins ; nuclear relaxation and ferrimagnetic resonance in single domain samples of impure YIG; nuclear relaxation in the Bloch walls of insulators. The results of our calculations are generally in good agreement with experiment. (author) [French] On se propose d'interpreter les resultats d'experiences de resonance magnetique nucleaire fates par divers auteurs sur des composes ferro et ferrimagnetiques du groupe du fer. Les problemes abordes sont les suivants: effets des champs dipolaires et de l'anisotropie de structure hyperfine; intensite des signaux; deplacement de frequence du a l'interaction de Suhl-Nakamura entre spins nucleaires; relaxation nucleaire et resonance ferrimagnetique dans les echantillons monodomaines de grenat de fer et d'yttrium impur; relaxation nucleaire dans les parois de Bloch des isolants. Les resultats des calculs sont generalement en bon accord avec l'experience. (auteur)

Mechanics and electronics as auxiliary techniques in nuclear research and exploitation; Mecanique et electronique auxiliaires de la recherche et de l'exploitation nucleaire

Energy Technology Data Exchange (ETDEWEB)

Weill, J. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre d' Etudes nucleaires de Saclay, Departement Electronique, Groupe Controle des Reacteurs (France)

1959-07-01

Electronics and mechanics form the basic techniques used in the field of measurement and control in nuclear physics experiments, and in nuclear machine installations. The delegate describes some instruments typical of the use of these techniques in the fields of calculation, detection, amplification and nuclear Installations. Reprint of a paper published in 'Bulletin S.F.M.' n. 25 (3. quarter 1957) [French] L'electronique et la mecanique constituent les techniques de base utilisees clans le domaine des mesures et du controle effectues dans les experiences de physique nucleaire et dans les installations des engins nucleaires. Le Conferencier decrit plusieurs appareils caracteristiques de l'emploi de ces techniques dans les domaines du calcul, des detecteurs, de l'amplification et des lnstallations nucleaires. Reproduction d'un article publie dans le 'Bulletin S.F.M.' n. 25 (3e trimestre 1957)

Contribution to the study of nuclear resonance in magnetic media (1963); Contribution a l'etude de la resonance nucleaire dans les milieux magnetique (1963)

Energy Technology Data Exchange (ETDEWEB)

Hartmann-Boutron, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-06-15

An attempt is made to interpret the results of nuclear magnetic resonance experiments made by various workers on ferro and ferrimagnetic compounds of the iron group. The problems encountered are the following: effects of the dipolar fields and the hyperfine structure anisotropy; signal intensity; frequency pulling due to the Suhl-Nakamura interaction between nuclear spins ; nuclear relaxation and ferrimagnetic resonance in single domain samples of impure YIG; nuclear relaxation in the Bloch walls of insulators. The results of our calculations are generally in good agreement with experiment. (author) [French] On se propose d'interpreter les resultats d'experiences de resonance magnetique nucleaire fates par divers auteurs sur des composes ferro et ferrimagnetiques du groupe du fer. Les problemes abordes sont les suivants: effets des champs dipolaires et de l'anisotropie de structure hyperfine; intensite des signaux; deplacement de frequence du a l'interaction de Suhl-Nakamura entre spins nucleaires; relaxation nucleaire et resonance ferrimagnetique dans les echantillons monodomaines de grenat de fer et d'yttrium impur; relaxation nucleaire dans les parois de Bloch des isolants. Les resultats des calculs sont generalement en bon accord avec l'experience. (auteur)

Rapport de frais de 2015-2016 pour Scott Gilmore | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2015-2016 pour Scott Gilmore. Total des frais de déplacement : CAD$31.46. Télécharger la version PDF de ce rapport. 13 juillet 2015 au 14 juillet 2015. CAD$31.46. Ce que nous faisons · Financement ...

Scientific report 1998; Rapport scientifique 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Nucleaires'', (DRN) during the year 1998. DRN is one of the CEA Institution. This report is divided in three main parts: the DRN scientific programs, the scientific and technical publications (with abstracts in english) and economic data on staff, budget and communication. Main results of the Department, for the year 1998, are presented giving information on the reactors technology and safety, the neutronics, the transmutation and the hybrid systems, the dismantling and the sites improvement, the nuclear accidents, the nuclear matter transport, the thermonuclear fusion safety, the fuel cladding materials and radioactive waste control. (A.L.B.)

Scientific report 1998; Rapport scientifique 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Nucleaires'', (DRN) during the year 1998. DRN is one of the CEA Institution. This report is divided in three main parts: the DRN scientific programs, the scientific and technical publications (with abstracts in english) and economic data on staff, budget and communication. Main results of the Department, for the year 1998, are presented giving information on the reactors technology and safety, the neutronics, the transmutation and the hybrid systems, the dismantling and the sites improvement, the nuclear accidents, the nuclear matter transport, the thermonuclear fusion safety, the fuel cladding materials and radioactive waste control. (A.L.B.)

Training in Compensatory Strategies Enhances Rapport in Interactions Involving People with Möbius Syndrome

Directory of Open Access Journals (Sweden)

John eMichael

2015-10-01

Full Text Available In the exploratory study reported here, we tested the efficacy of an intervention designed to train teenagers with Möbius Syndrome (MS to increase the use of alternative communication strategies (e.g. gestures to compensate for their lack of facial expressiveness. Specifically, we expected the intervention to increase the level of rapport experienced in social interactions by our participants. In addition, we aimed to identify the mechanisms responsible for any such increase in rapport. In the study, five teenagers with MS interacted with three naïve participants without MS before the intervention, and with three different naïve participants without MS after the intervention. Rapport was assessed by self-report and by behavioral coders who rated videos of the interactions. Individual nonverbal behavior was assessed via behavioral coders, while verbal behavior was automatically extracted from the sound files. Alignment was assessed using cross recurrence quantification analysis and mixed effects models. The results showed that observer-coded rapport was greater after the intervention, whereas self-reported rapport did not change significantly. Observer-coded gesture and expressivity increased in participants with and without MS, while overall linguistic alignment decreased. Fidgeting and repetitiveness of verbal behavior also decreased in both groups. In sum, the intervention may impact nonverbal and verbal behavior in participants with and without MS, increasing rapport as well as overall gesturing, while decreasing alignment.

Considering Face, Rights, and Goals: A Critical Review of Rapport Management in Facilitator-Guided Simulation Debriefing Approaches.

Science.gov (United States)

Loo, May Eng; Krishnasamy, Charmaine; Lim, Wee Shiong

2018-02-01

The rapport between facilitators and learners contributes to a conducive learning environment during simulation debriefing, but a theory to guide rapport management (RM) is lacking. The RM model is a potentially relevant conceptual framework because it describes three interrelated components of rapport-face, rights, and goals-which, when threatened, affect the rapport between interactants. This critical review explores how studies in the simulation debriefing literature describing postevent facilitator-guided debriefing approaches can be viewed through the lens of the RM model. All 34 identified studies alluded to at least one component of rapport, with less than half alluding to all three. There is preliminary evidence that the management of all three components of rapport during debriefing may contribute to improving short-term learning outcomes. Future studies could explore how the RM model can be used to guide debriefing approaches in various contexts and clarify why or how these approaches work.

Gas-flow detector for uranium contamination on finned-can surface of a reactor fuel; Detecteur a courant gazeux pour deceler la contamination en uranium des nervures des gaines de combustible nucleaire; Gazopotochnyj detektor zagryazneniya uranom rebristoj poverkhnosti obolochki reaktornykh teplovydelyayushchikh ehlementov; Detector de flujo gaseoso para medir la contaminacion de uranio en la superficie de la vaina de aletas de los elementos combustibles para reactores

Energy Technology Data Exchange (ETDEWEB)

Miwa, H; Shiojiri, T; Maeda, Y [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)

1962-04-15

Calder Hall-type reactor-fuel and all JRR-3 fuels are to be inspected by this counter. (author) [French] Le detecteur a courant gazeux presente par les auteurs est un compteur proportionnel a grille, specialement concu pour deceler la contamination en uranium des nervures des gaines de combustible nucleaire. Un compteur proportionnel classique, compose seulement d'une cathode et d'un collecteur, n'est guere capable de deceler les particules alpha emises par l'uranium contaminant une surface rugueuse telle que les nervures d'une gaine de combustible nucleaire, par suite du manque d'uniformite du champ electrique pres de la surface. C'est pourquoi les auteurs ont construit un compteur proportionnel a grille. Cet appareil, de forme cylindrique, comprend le combustible, une grille, des collecteurs et une cathode, tous les elements etant disposes suivant le meme axe. Le combustible est place au centre de la grille a laquelle on applique une tension negative. L'espace entre le combustible et la grille sert de collecteur d'ions. La grille, faite de fils paralleles minces en tungstene, disposes suivant un cylindre autour du combustible, est reliee a la terre. Les collecteurs sont constitues de 16 minces fils de tungstene disposes de la meme maniere que la grille, mais chaque fil est isole electriquement des autres. Tous les collecteurs sont interconnectes par des resistances de 5 x 10{sup 4} ohms et relies au positif de la haute tension par une resistance. L'espace entre la grille, les collecteurs et la cathode sert a la multiplication du gaz, tout comme dans un compteur proportionnel classique. Chaque resistance de 5 x 10{sup 4} ohms isole la capacite parasite de chaque collecteur. La sortie du detecteur est couplee a un amplificateur a faible impedance d'entree. La faible impedance d'entree diminue aussi l'influence facheuse de la capacite parasite du circuit d'entree. Il en resulte un rapport favorable signal/bruit de fond, ce qui permet une bonne detection des particules

La discussion pacifique comme rapport à la langue Française sur wikilf

Directory of Open Access Journals (Sweden)

Léda Mansour

2017-07-01

Full Text Available Cet article veut participer aux études sur le rapport des locuteurs à leur propre langue, ici la langue française. Alors que les études sur la langue pointent un lien “passionnel” qui prendra plusieurs formes: rapport puriste (parler sans faire des fautes, rapport a­ ectif (les mythes de beauté, d’ordre et de clarté, rapport idéologique (défendre sa langue, il existe, ailleurs, des lieux “pacifi ques” où la langue n’est pas disputée mais discutée. Nous avons choisi de travailler sur le site de création langagière WikiLf; c’est en créant un nouveau mot que l’on est le plus exposé à notre façon de voir/penser notre langue. Notre analyse se centre sur l’usage du métalangage laissant émerger un certain savoir sur la langue capable de traduire autrement le rapport à sa propre langue. Nous avons démontré qu’il existe un rapport plutôt spontané des locuteurs francophones qui semble dénué de toute passion, éloigné des postures normatives. Les wikistes donnent l’exemple d’une communauté qui pacifi quement met en discussion la langue française, ce qui représente d’abord un objet de réfl exion, mais encore un choix de recherche perme ant de nous positionner afi n de rendre compte (prendre en compte d’une relation plus souple des usagers de la langue française.

Activity report 1999; Rapport d'activites 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1999. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Training in Compensatory Strategies Enhances Rapport in Interactions Involving People with Möbius Syndrome

DEFF Research Database (Denmark)

Michael, John; Bogart, Kathleen; Tylén, Kristian

2015-01-01

, and with three different naïve participants without MS after the intervention. Rapport was assessed by self-report and by behavioral coders who rated videos of the interactions. Individual nonverbal behavior was assessed via behavioral coders, while verbal behavior was automatically extracted from the sound...... files. Alignment was assessed using cross recurrence quantification analysis and mixed effects models. The results showed that observer-coded rapport was greater after the intervention, whereas self-reported rapport did not change significantly. Observer-coded gesture and expressivity increased...

Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

Energy Technology Data Exchange (ETDEWEB)

Gauthron, M; Guibert, B [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

Development and testing of the EDF-2 reactor fuel element; Essais et mise au point de l'element combustible pour le reacteur EDF-2

Energy Technology Data Exchange (ETDEWEB)

Delpeyroux, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Furhmann, R [Societe Industrielle de Combustible Nucleaire (France)

1964-07-01

rassemble les etudes qui ont ete necessaires pour mener a bien la definition de l'element combustible EdF 2. Apres un bref rappel des caracteristiques du reacteur EdF 2 et des options preliminaires ayant permis de fixer un avant-projet d'element combustible, on aborde les etudes proprement dites: - Etudes uranium: essais de passage d'une couronne interne du tube en phase {beta}, flechage du tube sous l'action d'une force concentree, soudage des pastilles d'extremites et verification de leur etancheite. La tenue du tube a l'ecrasement et la resistance des pastilles a l'enfoncement sous l'action de la pression externe sont etudiees en detail dans un autre rapport CEA - Etudes gaine: rappel des conditions de fabrication et verification de l'etancheite de la gaine, tenue des ailettes au fluage sous l'action du courant gazeux - Etudes d'extremites: fluage en compression et soudage des bouchons a la gaine. - Etudes cartouche: determination des caracteristiques des gorges d'ancrage gaine-combustible et des conditions de gainage, verification de la tenue au cyclage thermique de l'element combustible, determination de la chute de temperature au contact gaine-combustible traitee en detail dans un autre rapport CEA, - Etudes de l'ensemble: les etudes se rapportant a la chemise de graphite, au support et aux vibrations de la cartouche ont ete traitees par le service des Etudes Mecaniques et Thermiques (Section de Mecanique), Dans ce domaine, la Section d'Etude d'Elements Combustibles a etudie la tenue des centreurs sous l'action du courant gazeux. L'aboutissement des etudes est constitue par le dessin de l'element combustible, le schema de fabrication et les normes de fabrication. La validite de l'ensemble de ces essais hors pile sera confirmee par des assais en pile qui sont en cours et par l'irradiation des elements dans le reacteur EdF 2 lui-meme. En conclusion, on donne l'orientation des etudes pour l'amelioration de l'element combustible et la definition d'un element combustible

Rapport, Motivation, Participation, and Perceptions of Learning in U.S. and Turkish Student Classrooms: A Replication and Cultural Comparison

Science.gov (United States)

Frisby, Brandi N.; Slone, Amanda R.; Bengu, Elif

2017-01-01

Building on previous rapport research, Hofstede's dimensions of culture, and calls for culture-centered instructional research, this study examined instructor-student rapport in U.S. and Turkish college classrooms. U.S. participants (N = 143) and Turkish participants (N = 185) completed measures of rapport, state motivation, participation, and…

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J; Moulle, N; Dutheil, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

The economic advantage of electricity-generating nuclear stations decreases when their size decreases. However, when a counter-pressure turbine is joined on to a reactor and the residual heat can be properly used, it can be shown that fairly low capacity nuclear equipment may compete with conventional equipment under certain realistic enough conditions. The aim of this paper is to define these special conditions under which nuclear energy can be profitable. They are connected with the location and the general economic environment of the station, the pattern of the electricity and heat demands it must meet, the level of fuel and specific capital costs, nuclear and conventional. These conditions entail certain technical and economic specifications for the reactors used in this way otherwise they are unlikely to be competitive. In addition, these results are referred to the potential steam and electricity market, which leads us to examine certain uses for the heat generated by double purpose power stations; for example, to supply combined industrial plants, various types of town heating and for removal of salt from sea water. (authors) [French] L'interet economique de centrales nucleaires productrices d'electricite decroit lorsque la puissance decroit. Cependant, lorsqu'on associe une turbine a contrepression a un reacteur et qu'il est possible d'utiliser dans de bonnes conditions la chaleur residuelle, on peut montrer que dans certaines conditions assez realistes, des equipements nucleaires d'une puissance unitaire peu elevee peuvent etre competitifs avec des equipements conventionnels. Cette communication a donc pour but de mettre en evidence quelles sont ces conditions particulieres de rentabilite de l'energie nucleaire. Elles sont liees a la localisation de la centrale et a son contexte economique general, a la structure de la demande d'energie electrique et thermique a laquelle elle doit satisfaire, au niveau des couts des combustibles et des investissements

Economic aspects of electricity and industrial heat generating reactors; Aspect economique des reacteurs produisant de l'electricite et de la chaleur industrielle

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J.; Moulle, N.; Dutheil, F. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Aldebert, J. [Institut National des Sciences et Techniques Nucleaires (INSTN), CEA Saclay, 91 - Gif sur Yvette (France)

1964-07-01

combustibles et des investissements specifiques nucleaires et classiques. Ces conditions de rentabilite conduisent a admettre pour les reacteurs ainsi utilises certaines caracteristiques techniques et economiques hors desquelles la competition est improbable. On situe, d'autre part, ces resultats par rapport au marche potentiel de la vapeur et de l'electricite et on est ainsi conduit a examiner certaines utilisations de la chaleur des centrales mixtes telles que l'alimentation de complexes industriels, de divers types de chauffage urbain ou du dessalement des eaux de mer. (auteurs)

Mannerisms of the Elderly and Approaches to Rapport.

Science.gov (United States)

French, Warren A.; And Others

1980-01-01

Many older adults react to old age with empirically identified distinguishable mannerisms. Using these mannerisms, or behavior patterns, as a basis for rapport, gerontologists can: (1) uncover causes of adjustment problems; (2) assess seriousness of problems; and (3) implement counseling suggestions. (Author/JAC)

The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay

International Nuclear Information System (INIS)

Debiesse, J.

1958-01-01

The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' was created (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author) [fr

Report from the working group on combustion of domestic animal manure fractions; Rapport fra arbejdsgruppen om afbraending af fraktioner af husdyrgoedning

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-06-01

During the past few years there has been a considerable development of new technology for treatment of domestic animal manure. The development implies that environmental problems connected with storage and use of domestic animal manure for fertilization are reduced. Through several years experiences with utilization of domestic animal manure's energy potential in biogas plants have been compiled, and the technological basis for connecting slurry separation and biogas production is present. In order to promote this development, the agricultural sector has a growing desire to be able to dispose of parts from the separated slurry through combustion, hereby using the energy content to the energy production. However, there are a number of barriers that make combustion of domestic animal manure impossible. In order to uncover existing barriers for combustion of domestic animal manure fractions the Danish Minister of food appointed an inter ministerial committee on 30 March 2005. The committee should: 1. Describe the regulations within the ministerial areas that affect combustion of domestic animal manure, and also describe the regulations that act as barriers, 2. Describe binding international agreements, directives and regulations that affect combustion of domestic animal manure and which of these that act as barriers, 3. Evaluate the potential for regulation adjustments and other actions, that might further the development of sustainable energy production in which domestic animal manure is a part, 4. Evaluate socio-economic pros and cons in the light of environmental and climatic impacts, and 5. Describe estimated governmental financial consequences of potential adjustments of regulations and other actions. (BA)

Nuclear program of Iran. Towards de-escalation of a nuclear crisis. Advisory letter; Nucleair programma van Iran. Naar de-escalatie van een nucleaire crisis. Briefadvies

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-04-15

The Dutch government, partly at the request of the House of Representatives (Second Chamber), the AIV asked to give an opinion about the position of Iran in the region and the role of the nuclear program of Iran in the geopolitical relations, in view of the most recent developments [Dutch] De Nederlandse regering heeft, mede op verzoek van de Tweede Kamer der Staten-Generaal, de AIV gevraagd advies uit te brengen over de positie van Iran in de regio en de rol van het nucleaire programma van Iran in de geopolitieke verhoudingen hierin, mede gelet op de meest recente ontwikkelingen.

Le coût par QALY rapporté au PIB (CQP): suggestion d'un nouvel ...

African Journals Online (AJOL)

Le coût par QALY rapporté au PIB (CQP): suggestion d'un nouvel indice économique évaluant l'impact réel du coût du bénéfice des molécules onéreuses en oncologie par rapport aux moyens économique d'un pays.

Activity report 1999; Rapport d'activites 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The aim of this report is to outline the main developments of the ''Departement des Reacteurs Experimentaux'', (DRE) during the year 1999. DRE is one of the Department of the ''Direction des Reacteurs Nucleaires'', itself depending of the CEA Institution. After a presentation of the year highlights, this report gathers the main research and development programs. The second part concerns the production of radioisotopes, the silicon doping, the neutron radiography, the Orphee experiments and the activation analysis. The installations management, the closed reactors improvement program and the effluents and wastes processing of Grenoble, are presented in the other parts. Data on staff, budget and safety are also provided. (A.L.B.)

Material movement of medium surrounding an underground nuclear explosion; Mouvement materiel du milieu environnant une explosion nucleaire souterraine

Energy Technology Data Exchange (ETDEWEB)

Guerrini, C; Garnier, J L [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

The results of measurements of the mechanical effects in the, intermediate zone around underground nuclear explosions in Sahara granite are presented. After a description of the main characteristics of the equipment used, the laws drawn up using experimental results for the acceleration, the velocity, and the material displacement are presented. These laws are compared to those published in other countries for nuclear tests in granite, in tuff and in alluvial deposits. (authors) [French] Les resultats de mesures d'effets mecaniques en zone intermediaire autour d'essais nucleaires souterrains dans le granite du Sahara sont exposes. Apres avoir decrit, dans leurs grandes lignes, les materiels utilises, on presente les lois etablies avec les resultats experimentaux pour l'acceleration, la vitesse et le deplacement materiel. Ces lois sont comparees a celles publiees a l'etranger pour des essais nucleaires dans le granite, le tuf et les alluvions. (auteur)

Statistical pulses generator. Application to nuclear instrumentation (1962); Generateur d'impulsions aleatoires. Application a l'instrumentation nucleaire (1962)

Energy Technology Data Exchange (ETDEWEB)

Beranger, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

This report describes a random pulses generator adapted to nuclear instrumentation. After a short survey on the statistical nature of electronic signals, the different ways for generating pulses with a Poisson's time-distribution are studied. The final generator built from a gaseous thyratron in a magnetic field is then described. Several tests are indicated : counting-rate stability, Pearson's criterion, distribution of time-intervals. Applications of the generator in 'whole testing' of nuclear instrumentation are then indicated for sealers, dead time measurements, time analyzers. In this application, pulse-height spectrums have been made by Poissonian sampling of a recurrent or random low-frequency signal. (author) [French] Cette etude decrit un generateur d'impulsions aleatoires et ses applications a l'instrumentation nucleaire. Apres un bref rappel sur la nature statistique des signaux en electronique nucleaire, sont passes en revue les principaux moyens d'obtenir des impulsions distribuees en temps suivant une loi de Poisson. Le generateur utilisant un thyratron a gaz dans un champ magnetique est ensuite decrit; diverses methodes de test sont appliquees (stabilite du taux de comptage, criterium de Pearson, spectre des intervalles ds temps). Les applications du generateur a l'electronique nucleaire dans le domaine des 'essais globaux' sont indiques: test des echelles de comptage et mesure des temps morts, test des analyseurs en temps apres division du taux de comptage par une puissance de deux, test des analyseurs multicanaux en amplitude. Pour cette derniere application, on a realise des spectres d'amplitudes suivant une loi connue, par echantillonnage poissonien d'un signal basse frequence recurrent ou aleatoire. (auteur)

Activity report 1998; Rapport d'activite 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The ''Institut de Protection et de Surete Nucleaire'' (IPSN), carries out researches and expert studies needed to manage nuclear risks and their consequences on people and environment. These activities cover the installation safety, the radioactive matter transport, the public health and environmental control, the nuclear matters safety and control and the crisis situation management. The IPSN have got also a mission of public information and participates to international actions in the domain of scientific researches or expert's report. This annual report presents the highlights of the year 1998, information on staff, budgets and geographical situation. Then technical and scientific papers gathers the activities of the year covered by the IPSN: the ''Free Tribune'', installations and radioactive wastes safety, crisis and nuclear matter management, public health and environment control, international cooperation. (A.L.B.)

Rapport: The Value for Money Discourse: Risks and Opportunities ...

International Development Research Centre (IDRC) Digital Library (Canada)

optimisation des ressources exerce également une influence croissante sur ce qui revêt de l'importance pour les bailleurs de fonds. Le rapport The Value for Money Discourse: Risks and Opportunities for R4D a pour but de ...

RAPPORT-BUILDING THROUGH CALL IN TEACHING CHINESE AS A FOREIGN LANGUAGE: AN EXPLORATORY STUDY

Directory of Open Access Journals (Sweden)

Wenying Jiang

2005-05-01

Full Text Available Technological advances have brought about the ever-increasing utilisation of computer-assisted language learning (CALL media in the learning of a second language (L2. Computer-mediated communication, for example, provides a practical means for extending the learning of spoken language, a challenging process in tonal languages such as Chinese, beyond the realms of the classroom. In order to effectively improve spoken language competency, however, CALL applications must also reproduce the social interaction that lies at the heart of language learning and language use. This study draws on data obtained from the utilisation of CALL in the learning of L2 Chinese to explore whether this medium can be used to extend opportunities for rapport-building in language teaching beyond the face-to-face interaction of the classroom. Rapport's importance lies in its potential to enhance learning, motivate learners, and reduce learner anxiety. To date, CALL's potential in relation to this facet of social interaction remains a neglected area of research. The results of this exploratory study suggest that CALL may help foster learner-teacher rapport and that scaffolding, such as strategically composing rapport-fostering questions in sound-files, is conducive to this outcome. The study provides an instruction model for this application of CALL.

Contribution to the study of thermal mixing between nuclear spin systems; Contribution a l'etude du melange thermique entre systemes de spins nucleaires

Energy Technology Data Exchange (ETDEWEB)

Goldmann, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-02-15

This work describes methods of dynamic nuclear polarization in solids based on the thermal mixing between nuclear spin systems. The description of the thermal mixing processes involves most of the fundamental aspects of the spin temperature theory. The experiments, conducted with paradichlorobenzene and para-dibromobenzene, yield a detailed confirmation of the theoretical predictions. (author) [French] Ce travail decrit des methodes de polarisation dynamique nucleaire dans les solides basees sur le melange thermique entre systemes de spins nucleaires. La description des processus de melange thermique met en jeu la plupart des aspects fondamentaux de la theorie de la temperature de spin. Les experiences, realisees avec du paradichlorobenzene et du paradibromobenzene, apportent une confirmation detaillee des previsions theoriques. (auteur)

Design of the fuel element 'snow-flake' in uranium oxide, canned with aluminium, for the experimental reactor EL 3 (1960); Etude d'un element combustible en oxyde d'uranium gaine d'aluminium, type ''cristal de neige'' pour la pile EL 3 (1960)

Energy Technology Data Exchange (ETDEWEB)

Gauthron, M.; Guibert, B. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

This report sums up the main studies have been carried out on the fuel element 'Snowflake' (uranium oxide, canned with aluminium), designed to replace the present element of the experimental reactor EL3 in order to increase the reactivity without modifying the neutron flux/thermal power ratio. (author) [French] Ce rapport resume les principales etudes qui ont ete faites sur l'element combustible 'Cristal de Neige' (a oxyde d'uranium, gaine d'aluminium) destine a remnlacer l'element actuel du reacteur experimental EL3, afin d'en augmenter la reactivite sans modifier le rapport flux neutronique-puissance thermique. (auteur)

Lacan and Adolescence: The Contemporary Clinic of the "Sexual Non-rapport" and Pornography.

Science.gov (United States)

Ouvry, Olivier

2017-01-01

This article explores two clinical phenomena-pornography and conspiracy thinking-that are highly relevant today and can be observed specifically among adolescent boys in the early stages of post-puberty: conspiracy thinking and the viewing of pornographic videos. It shows that the Lacanian concepts of the Real (of puberty) and the sexual non-rapport help us understand the psychopathological aspects of these two phenomena. Watching pornographic material becomes equivalent to a conspiracy theory about the sexual non-rapport; both in fact deny the effect of what puberty introduces as radically new.

Situation des personnes transgenres par rapport au VIH/IST en Suisse : rapid assessment

OpenAIRE

Bize, R.; Koutaissoff, D.; Dubois-Arber, F.

2013-01-01

Ce rapport permet d'identifier le sous-groupe des personnes transgenres pratiquant ou ayant pratiqué le travail du sexe comme une population clairement exposée à un risque notoirement élevé d'infection par le VIH et les IST. L'ampleur rapportée du phénomène justifie pleinement l'inclusion de cette population dans le dispositif de surveillance comportementale du VIH et des autres IST, mais également la réalisation urgente d'actions de prévention communautaire. Par contre, il ne nous permet pas...

A Cross-Cultural Pragmatic Study of Rapport-Management Strategies in Chinese and English Academic Upward Request Emails

Science.gov (United States)

Zhu, Wuhan

2017-01-01

This article discusses and compares how Chinese and English postgraduate students manage a harmonious relationship with university instructors by managing rapport and doing relational work in their academic request emails. The rapport-management strategies were explored and then further evaluated in relation to the taxonomies of relational work…

Droit administratif international - amélioration des rapports ...

International Development Research Centre (IDRC) Digital Library (Canada)

La recherche portant sur la façon dont les rapports avec les institutions et entre celles-ci sont susceptibles de compromettre la capacité des pays en développement de concrétiser leurs objectifs et réformes réglementaires permettra de jeter un éclairage sur le domaine, jusqu'ici négligé, du droit et du développement.

Imminent perspectives for industrial application of atomic energy; Perspectives imminentes de l'application industrielle de l'energie atomique

Energy Technology Data Exchange (ETDEWEB)

Kowarski, L [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

This conference raises an inventory of industrial applications and their perspectives for the year 1955. The speaker extrapolate for the forthcoming years the evolution of the role of the nuclear, the nuclear fuel, the different, types of atomic reactors and the state of advancement for different countries. (M.B.) [French] Cette conference dresse un etat des lieux des applications industrielles et de leurs perspectives pour l'annee 1955. L'orateur aborde entre autre l'evolution du role du nucleaire dans les annees a venir, le combustible nucleaire, les differents types de piles atomiques et l'etat d'avancement des differents pays. (M.B.)

Activity report 1998; Rapport d'activite 1998

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The ''Institut de Protection et de Surete Nucleaire'' (IPSN), carries out researches and expert studies needed to manage nuclear risks and their consequences on people and environment. These activities cover the installation safety, the radioactive matter transport, the public health and environmental control, the nuclear matters safety and control and the crisis situation management. The IPSN have got also a mission of public information and participates to international actions in the domain of scientific researches or expert's report. This annual report presents the highlights of the year 1998, information on staff, budgets and geographical situation. Then technical and scientific papers gathers the activities of the year covered by the IPSN: the ''Free Tribune'', installations and radioactive wastes safety, crisis and nuclear matter management, public health and environment control, international cooperation. (A.L.B.)

Nuclear Materials Management and its Relationship to Nuclear Safety and Criticality Control; La Gestion des Matieres Nucleaires et ses Rapports avec la Securite Nucleaire et le Controle de la Criticite; Obrashchenie s yadernymi materialami i ego svyaz' s yadernoj bezopasnost'yu i kontrolem nad kritichnost'yu; La Administracion de Materiales Nucleares y sus Relaciones con la Seguridad Nuclear y el Control de la Criticidad

Energy Technology Data Exchange (ETDEWEB)

Tingey, F. H. [Phillips Petroleum Company, Idaho Falls, ID (United States)

1966-02-15

dictated by the technical considerations and familiar with the operational limitations. The administrative problems are solved through procedural restrictions placed by the supervisor. The NMM office can be most valuable in further support to the supervisor in these activities. The primary responsibility of this office is to alert responsible supervision to potentially hazardous situations as indicated either from information made available through the routine processing of accountability data or from material balance calculations. Any information pertaining to criticality studies as requested from the NMM office must be accurate and precise. A vigorous inventory management policy must be pursued to lessen the problems presented by accumulation of fissile materials. Internal audit by the NMM staff of inventory holdings can also serve to verify adherence to safeguard procedures. A vigorous orientation programme can be implemented by the NMM staff in its dealing with those individuals handling nuclear materials to make them more aware of the hazards involved. The integration of the NMM group into the general criticality safeguard problems at the NRT and has provided an effective system for assisting the line supervision in discharging this very important responsibility. (author) [French] Il est essentiel pour tous ceux qui travaillent dans l'industrie nucleaire de savoir comment eviter que des matieres nucleaires ne se trouvent rassemblees en quantites, selon une geometrie ou dans un milieu tels qu'elles puissent donner lieu a une reaction neutronique en chaine. Ceci interesse tout particulierement ceux qui, dans l'exercice de leurs fonctions, sont responsables de la manipulation, du transfert et de l'entreposage des matieres fissiles. Ces memes personnes participent au systeme de gestion des matieres nucleaires. Elles ont au premier chef la responsabilite de fournir et de recevoir les donnees comptables par l'intermediaire du service de gestion des matieres nucleaires

Saving Face: Managing Rapport in a Problem-Based Learning Group

Science.gov (United States)

Robinson, Leslie; Harris, Ann; Burton, Rob

2015-01-01

This qualitative study investigated the complex social aspects of communication required for students to participate effectively in Problem-Based Learning and explored how these dynamics are managed. The longitudinal study of a group of first-year undergraduates examined interactions using Rapport Management as a framework to analyse communication…

IPSN activity report 1999; Rapport d'activite de l'IPSN 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The IPSN (Institut de Protection et de Surete Nucleaire) carries out for the Government, studies and inspections on nuclear installations at many life steps (design, realisation, exploitation, shutdown and dismantling). To obtain quality researches, the Institut performs studies in all domains concerned by the safety and its improvement. The main projects of the year 1999, in the following topics are presented: the nuclear installations and the radioactive wastes safety, the crisis and nuclear materials management, the human and the environment protection, the international activities and cooperation, the quality insurance. It provides also information on the cooperation, the budget, the human resource policy and the communication activities. (A.L.B.)

The 'Pole Nucleaire Bourgogne' for developing the nuclear components industry

International Nuclear Information System (INIS)

Kottmann, G.

2012-01-01

The 'Pole Nucleaire Bourgogne' (PNB) is a high-technology and heavy industries cluster in Burgundy with an international calling. It aims at innovating, educating and federating in order to place the French nuclear industry in a leading position. PNB gathers 76 small-, and medium-sized enterprises, most of them operating in the metal sector, in design and in the control/measuring sector. The aim of PNB is to make enterprises work and cooperate on specific topics according to their sectors of activities and their skills. PNB has identified 3 domains of strategical innovations: -) ecological manufacturing and durability of heavy components, -) controls for high performance components, and -) maintenance and dismantling techniques in hostile environments. The various industry sectors represented in PNB allows a cross-fertilization between high-tech industries (aeronautics, energy, transportation)

Study methods for the drillings around the underground nuclear explosions in the Sahara. Part 1. study of rock samples; Methodes d'etude des forages realises autour des explosions nucleaires souterraines au Sahara. Premiere partie: etude des echantillons de roche

Energy Technology Data Exchange (ETDEWEB)

Derlich, S [Commissariat a l' Energie Atomique, Bruyers-le-Chatel (France). Centre d' Etudes

1969-07-01

An examination of the mechanical effects produced on rocks by an underground nuclear explosion calls for the use of particular means of exploration which are described in this report, special attention being paid to the equipment used in connection with the French nuclear tests in the Sahara. The drilling methods used (rotary and turbo-drilling) are adapted to the particular conditions of the sampling programme, to the radioactivity and to the temperature in the region of the explosion. A study of the samples makes it possible to obtain the new characteristics of the rock and to assess the chemical and mechanical transformations which it has undergone. An examination of the core obtained from the drilling, together with a knowledge of the drilling parameters (depth of the probe, sample recovery, etc...), makes it possible to study the extent and the characteristics of the zones which have been damaged to different degrees according to their distance from the zero point: cavity, strongly powdered zone, fractured zone, chimney, zones containing high stresses leading to a particular type of fracture of the cores. The problems connected with the interpretation of the results are also presented. (author) [French] L'examen des effets mecaniques provoques par une explosion nucleaire souterraine sur la roche necessite la mise en oeuvre de moyens d'exploration particuliers dont l'expose fait l'objet de ce rapport, essentiellement pour les moyens utilises autour des essais nucleaires francais au Sahara. Les methodes de forage (rotary et turboforage) sont adaptees aux conditions particulieres dues au programme d'echantillonnage, a la radioactivite et a la temperature regnant a proximite du point de tir. L'etude des echantillons permet la determination des nouveaux caracteres de la roche et de ses transformations chimique et mecanique. L'examen des carottes et l'utilisation des parametres de forage (cotes sondeurs, recuperation des echantillons, etc...) permettent d'etudier l

France's nuclear power programme; Le programme nucleaire francais

Energy Technology Data Exchange (ETDEWEB)

Cabanius, J [Electricite de France (EDF), 75 - Paris (France); Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

-increasing importance, by using the country's resources of natural uranium, and later plutonium, to the best ends. (authors) [French] Les perspectives d'evolution de la consommation d'energie electrique francaise confirment l'aggravation du deficit des ressources energetiques metropolitaines. Les centrales nucleaires doivent permettre de diminuer ce deficit si un certain nombre d'incertitudes actuelles sont levees. Le premier programme presente par MM AILLERET et TARANGER a la Conference de Geneve en 1955 visait la mise en service pour 1965 de 850 MWe; il a ete consacre au developpement de la filiere uranium naturel - graphite - gaz et s'acheve avec la realisation d'EDF 3, premiere unite capable de 500 MWe engagee dans le monde. Avant de passer du stade des prototypes a celui des duplications, ELECTRICITE DE FRANCE a decide, en accord avec le COMMISSARIAT A L'ENERGIE ATOMIQUE, la realisation d'EDF 4 qui, en reprenant la partie reacteur d'EDF 3 ainsi que l'appareil de chargement et de dechargement, l'ensemble de controle et divers materiels, apporte une innovation importante en incorporant les echangeurs et les soufflantes a l'interieur du caisson en beton precontraint contenant le coeur. En meme temps, les etudes se poursuivent dans cette meme filiere et laissent entrevoir les possibilites d'utiliser un nouvel element combustible annulaire dont l'emploi ameliorerait notablement les performances d'EDF 5. Dans la filiere eau lourde, la realisation d'EL 4 a Brennilis par le COMMISSARIAT A L'ENERGIE ATOMIQUE et ELECTRICITE DE FRANCE se poursuit. Les etudes d'un reacteur de 500 MWe de cette filiere ont deja commence. Dans la filiere a eau pressurisee, la centrale de CHOOZ est realisee en association par ELECTRICITE DE FRANCE et les Producteurs Belges. Enfin, le COMMISSARIAT A L'ENERGIE ATOMIQUE poursuit a Cadarache la realisation du surgenerateur 'Rapsodie' et les etudes d'un reacteur de puissance plus important. Ainsi, les connaissances techniques et economiques acquises dans ces diverses

Rapport social de service, client et valeur Service-based social relationships, customers and and value Vínculo social de servicio, cliente y valor

OpenAIRE

Philippe Zarifian

2013-01-01

Ce texte développe une double idée. La première est que l’on peut parler de « rapport social de service », au sens plein du concept de « rapport social », en en assumant toutes les implications et en le différenciant nettement de la notion de « relation de service ». La seconde, qui découle de la première, est que l’on peut parler de « composition » entre rapports sociaux différents, non réductibles l’un à l’autre. Nous montrons ainsi qu’il existe une composition entre rapport social de servi...

The 1989 annual report of the Institut de Physique Nucleaire-Orsay

International Nuclear Information System (INIS)

1989-01-01

The activity report of the Institut de Physique Nucleaire (Orsay-France) from 1 Sep 1988 to 1 Aug 1989 is presented. Theoretical and experimental investigations were carried out in the following fields: light and medium exotic nuclei, on line spectroscopy, discrete high spin states, new radioactivities, thermal fission, detection systems, giant resonances, high excitation energy structure, reaction mechanisms at energies below 10 MeV/u and at 200 MeV/u and their evolution between 10 and 100 MeV/u, meson production, transfer reactions, spin modes in nuclei, dibaryonic resonances, inelastic scattering of polarized protons. Research programs in the field of radiochemistry and relating to inter-disciplinary fields are included. The activities involving teaching, the lists of publications conferences, seminars and theses are presented [fr

Combustion

CERN Document Server

Glassman, Irvin

2008-01-01

Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

Le lancement canadien du Rapport sur les politiques alimentaires ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 mai 2018 ... Cet événement sera filmé, puis accessible en ligne sur la chaîne YouTube du CRDI. Le Rapport sur les politiques alimentaires mondiales 2018 passe en revue les principaux faits nouveaux et événements en matière de politiques alimentaires survenus au cours de l'année. D'éminents chercheurs ...

Programme ACCA : Rapport annuel 2009-2010 | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

À la lumière d'études de cas locales et ciblées consacrées à l'adaptation en Afrique, le présent rapport montre en quoi la participation des décideurs au processus de recherche les aide à mieux cerner ce processus et contribue à les mobiliser. Le programme ACCA est financé conjointement par le Centre de recherches ...

Calculation of the shock-wave in the region close to an underground nuclear explosion (method Cades); Calcul de l'onde de choc en zone proche d'une explosion nucleaire souterraine (methode cades)

Energy Technology Data Exchange (ETDEWEB)

Supiot, F; Brugies, J [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

The outline of a method is presented for calculating the characteristics of a shock wave produced by an underground nuclear explosion (pressure, wave velocity, velocity of the medium, energy left in the medium by the shock, etc.). By means of an application to a granitic medium and of a comparison with results obtained during French nuclear explosions, it has been possible to show the good agreement existing between the calculations and the experimental results. The advantages of such a method for studying the industrial applications of underground nuclear explosions are stressed. (authors) [French] On expose les grandes lignes d'une methode de calcul des caracteristiques de l'onde de choc issue d'une explosion nucleaire souterraine (pression, vitesse de l'onde, vitesse du milieu, energie deposee par le choc dans le milieu...). Une application a un milieu granitique et une comparaison aux resultats obtenus au cours d'explosions nucleaires francaises permet de montrer la bonne concordance entre le calcul et les resultats experimentaux. On souligne l'interet d'une telle, methode pour l'etude d'applications industrielles des explosions nucleaires souterraines. (auteurs)

Combustion

CERN Document Server

Glassman, Irvin

1997-01-01

This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

Heat exchange and pressure drop of herring-bone fin surfaces. Experimental cell results at constant wall temperature; Echange de chaleur et perte de charge de surfaces a ailettes en chevrons. Resultats experimentaux en cellule a temperature de paroi constante

Energy Technology Data Exchange (ETDEWEB)

NONE

1968-07-01

The increase in the specific power of nuclear reactors of the gas-graphite type has necessitated the use of high performance exchange surfaces for canning the fuel (natural uranium). For this, experiments were carried out on cans fitted with herring-bone fins, at constant wall temperature; a flow of water at 100 deg. C passes inside the can which is cooled externally by a flow of CO{sub 2} at 15 bars pressure. This experimental set-up makes it possible to compare the aero-thermal performances of the different cans with an accuracy of 5 per cent. This report presents the results obtained in the form of a friction coefficient f{sub 0} and mean Margoulis number m{sub 0} as a function of the Reynolds number Re{sub 0}, this latter varying from 3 x 10{sup 5} to 9 x 10{sup 5}. (authors) [French] L'augmentation de la puissance specifique des reacteurs nucleaires de la filiere graphite-gaz a necessite l'utilisation de surfaces d'echange a hautes performances pour gainer le combustible (uranium naturel). Dans cette optique, des gaines munies d'ailettes disposees en chevron ont ete experimentees a temperature de paroi constante: un courant d'eau a 100 deg. C circule a l'interieur de la gaine qui est refroidie exterieurement par un ecoulement de CO{sub 2} sous une pression de 15 bars. Cette methode experimentale permet de situer les performances aerothermiques des gaines les unes par rapport aux autres a 5 pour cent pres. Ce rapport presente les resultats obtenus sous la forme d'un coefficient de frottement f{sub 0} et d'un nombre de Margoulis moyen m{sub 0} en fonction du nombre de Reynolds Re{sub 0}, ce dernier pouvant varier de 3. 10{sup 5} a 9. 10{sup 5}. (auteurs)

Rapport de frais de 2016-2017 pour Chandra Madramootoo | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2016-2017 pour Chandra Madramootoo. Total des frais de déplacement : CAD$10,750.19. Réunion du Conseil des gouverneurs. 20 mars 2017 au 22 mars 2017. CAD$821.31. Réunion du Conseil des gouverneurs. 20 novembre 2016 au 23 novembre 2016. CAD$907.94. Initiation des nouveaux ...

La conflictualité des rapports de travail dans l’économie de la connaissance: une perspective identitaire

Directory of Open Access Journals (Sweden)

William Rojas-Rojas

2009-06-01

Full Text Available Cet article a pour objectif de mettre en avant l’irréductibilité du conflit dans les rapports de travail entre dirigeants et subordonnés au sein des entreprises les plus avancées des économies développées. La conflictualité dans les rapports de travail est envisagée dans une perspective identitaire s’appuyant sur le concept psychanalytique d’inhumanité. L’inhumanité au travail est définie comme la dimension de la condition humaine qui conduit l’individu à affirmer son identité par la négation partielle de la condition d’humanité d’autrui dans les rapports de travail. Les auteurs entendent ainsi montrer l’illusion managériale qui préside à la mise en place de programmes visant à a-conflictualiser les rapports de travail dans l’organisation. Pour les auteurs, ces programmes ne peuvent faire disparaître une inhumanité profondément ancrée dans les structures formelles et dans le système culturel, symbolique et imaginaire de l’organisation. La permanence de l’inhumanité dans les rapports de travail reflète l’existence de puissants obstacles psychiques et culturels s’opposant à la reconnaissance pleine et entière de la condition humaine au sein des organisations. L’impossibilité d’exprimer l’altérité dans son identité dans le champ organisationnel conduit à déplacer la pulsion agressive vers la violence non plus symbolique mais concrète. Et face à la violence, le management n’a ni emprise, ni outil de gestion. Comme le démontre l’histoire de l’humanité, seule la civilisation et la culture peuvent aboutir à mieux reconnaître et se reconnaître dans l’altérité.

Combustion engineering

CERN Document Server

Ragland, Kenneth W

2011-01-01

Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

Bijlage 3 bij RIVM-rapport 601714022 Specifieke verontreinigende en drinkwater relevante stoffen onder de Kaderrichtlijn water : Selectie van potentieel relevante stoffen voor Nederland

NARCIS (Netherlands)

Smit CE; Wuijts S; SEC

2012-01-01

Dit rapport is een bijlage bij rapport 601714022

Factsheets nieuwe stoffen
De 'factsheets' in deze bijlage zijn opgesteld in het Engels om de uitwisseling van informatie in internationaal verband te vergemakkelijken.

Rapport de frais de 2016-2017 pour Gordon Houlden | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2016-2017 pour Gordon Houlden. Total des frais de déplacement : CAD$3,444.37. Réunion du Conseil des gouverneurs. 15 mai 2016 au 16 mai 2016. CAD$979.19. Réunion du Conseil des ...

Rapport de frais de 2015-2016 pour Gordon Houlden | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2015-2016 pour Gordon Houlden. Total des frais de déplacement : CAD$2,798.04. Réunion du Conseil des gouverneurs. 16 novembre 2015 au 19 novembre 2015. CAD$1,093.39. Réunion du Conseil ...

Rapportering om going concern i den nye revisionspåtegning

DEFF Research Database (Denmark)

Seehausen, Jesper

2017-01-01

Artiklen omhandler revisors rapportering om going concern i den nye revisionspåtegning. Det er artiklens centrale budskab, at der i den nye revisionspåtegning alene er ændringer til, hvordan revisor skal rapportere om going concern i revisionspåtegningen. Der er derimod ikke ændringer til, hvornår...... revisor skal rapportere om going concern i revisionspåtegningen....

Combustion

CERN Document Server

Glassman, Irvin

1987-01-01

Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

Lignes directrices du CRDI pour la préparation du rapport technique

International Development Research Centre (IDRC) Digital Library (Canada)

fdieudonne

l'accord de subvention et doivent faire partie de tout rapport hébergé dans la ... questions de nature délicate ou confidentielle doivent être traitées par un échange .... les innovations relevant des sciences, de la recherche ou du savoir;.

Pulsating combustion - Combustion characteristics and reduction of emissions

Energy Technology Data Exchange (ETDEWEB)

Lindholm, Annika

1999-11-01

In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

Study of the chimney produced by an underground nuclear explosion; Etude de la cheminee creee par une explosion nucleaire souterraine

Energy Technology Data Exchange (ETDEWEB)

Derlich, S [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1969-07-01

Underground nuclear explosions lead to the formation of a cavity which is roughly of spherical shape. The roof of this cavity is unstable and collapses in most cases, leading to the formation of a chimney. The height and the diameter depend on the energy of the charge and on the nature of the surroundings. The chronology of the various stages can be determined by seismic observations. The interior of the chimney is filled, either partially or completely, with rubble earth. This phenomenon is of great importance as far as the use of nuclear explosions for industrial applications is concerned. (author) [French] Les explosions nucleaires souterraines creent une cavite de forme grossierement spherique. La voute de cette cavite est instable et s'effondre dans la plupart des cas, donnant lieu a la formation d'une cheminee. La hauteur et le diametre sont fonction de l'energie du tir et de la nature du milieu. La chronologie des evenements peut etre determinee par des observations seismiques. L'interieur des cheminees est occupe, en partie ou en totalite, par des eboulis. Ce phenomene presente un grand interet pour l'utilisation des explosions nucleaires a des fins industrielles. (auteur)

Contribution to the study of time-resolution in pulse electronics for nuclear physics: phase control circuits; Contribution a l'etude de la resolution en temps de l'electronique impulsionnelle pour physique nucleaire: les circuits de mise en phase

Energy Technology Data Exchange (ETDEWEB)

Cortet, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

Phase control circuits make it possible to improve quite markedly the time resolution in pulse electronics. They replace a random pulse, of which the time of arrival with respect to a reference zero is being measured, by another pulse whose phase is well determined with respect to that, of a clock taken as reference. The time spectrum of the output, delayed, can always be situated inside channels of width {delta}T defined by the clock. The time statistics of the events analyzed is always correct even if the transition time for the circuits defining the channels represents a large fraction of {delta}T: the coding of the time becomes perfect, The phase control circuits, used in precision chronometry, are widely applied in Nuclear Physics since the lime spectra obtained are representative, indirectly, of certain values which are required to be measured with great accuracy. A description is given of: the constitution and operation of phase control circuits; a chain with automatic analysis and automatic reading, built for testing these circuits. Finally the measurement results are given. (author) [French] Les circuits de mise en phase permettent d'ameliorer notablement la resolution en temps de l'electronique impulsionnelle. Ils substituent a une impulsion aleatoire, dont on cherche a mesurer l'instant d'arrivee par rapport a un instant pris pour origine, une autre impulsion dont la phase est bien determinee par rapport a celle d'une horloge prise comme reference. Le spectre temporel de sortie, retarde, peut toujours etre situe a l'interieur des canaux de largeur {delta}T, definis par l'horloge. La statistique temporelle des evenements analyses est toujours correcte, meme si la duree de transition des circuits definissant les canaux represente une grande fraction de {delta}T: le codage de temps devient parfait. Les circuits de mise en phase, utilises en chronometrie fine, sont tres employes en Physique Nucleaire car les spectres temporels oblenus sont representatifs

Detection and location of can rupture in reactors cooled by a flow of water; Detection et localisation des ruptures de gaines sur les reacteurs refroidis par circulation d'eau

Energy Technology Data Exchange (ETDEWEB)

Le Meur, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1968-07-01

This report brings together the principal methods of fission-product detection used for water reactors. The position, type and method of adjustment is given for each detector. The methods for localizing the defective elements are explained, in particular those using water sampling or decreases in the flux. A few installations are briefly described. They correspond to particular types of reactors using boiling, pressurized or cold water. Amongst the many methods used, it can be noted that when the fuel is resistant, the installations are fairly compact. In nuclear super-heated reactors on the other hand, the study of fuel behaviour calls for larger installations. An identification of defective elements exists when the reactor structure allows it. If this is not possible, a localization in a group of elements is obtained by a flux depression. (author) [French] Ce rapport rassemble les principales methodes de detection de produits de fission utilisees pour des reacteurs a eau. On indique pour les detecteurs leurs emplacements, leurs types, leurs reglages. On explique quelles sont les methodes de localisation des elements defectueux, en particulier celles utilisant des prelevements d'eau ou des depressions de flux. Quelques installations sont decrites sommairement. Elles correspondent a des types particuliers de reacteurs a eau bouillante, pressurisee ou froide. Parmi les nombreuses methodes utilisees, on constate que les installations sont peu importantes, lorsque le combustible est resistant. Par contre dans les reacteurs a surchauffe nucleaire l'etude du comportement du combustible necessite des installations plus importantes. Une identification d'elements defectueux existe lorsque la structure du reacteur le permet. A defaut une localisation dans un groupe d'elements est obtenue par depression de flux. (auteur)

Managing Psychiatrist-Patient Relationships in the Digital Age: a Summary Review of the Impact of Technology-enabled Care on Clinical Processes and Rapport.

Science.gov (United States)

Parish, Michelle Burke; Fazio, Sarina; Chan, Steven; Yellowlees, Peter M

2017-10-27

Participatory medicine and the availability of commercial technologies have given patients more options to view and track their health information and to communicate with their providers. This shift in the clinical process may be of particular importance in mental healthcare where rapport plays a significant role in the therapeutic process. In this review, we examined literature related to the impact of technology on the clinical workflow and patient-provider rapport in the mental health field between January 2014 and June 2017. Thirty three relevant articles, of 226 identified articles, were summarized. The use of technology clinically has evolved from making care more accessible and efficient to leveraging technology to improve care, communication, and patient-provider rapport. Evidence exists demonstrating that information and communication technologies may improve care by better connecting patients and providers and by improving patient-provider rapport, although further research is needed.

Rapport de frais de 2016-2017 pour Sophie D'Amours | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2016-2017 pour Sophie D'Amours. What we do · Funding · Resources · About IDRC. Knowledge. Innovation. Solutions. Careers · Contact Us · Site map. Sign up now for IDRC news and views sent directly to your inbox each month. Subscribe · Copyright · Open access policy · Privacy policy · Research ...

IPSN activity report 1999; Rapport d'activite de l'IPSN 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

The IPSN (Institut de Protection et de Surete Nucleaire) carries out for the Government, studies and inspections on nuclear installations at many life steps (design, realisation, exploitation, shutdown and dismantling). To obtain quality researches, the Institut performs studies in all domains concerned by the safety and its improvement. The main projects of the year 1999, in the following topics are presented: the nuclear installations and the radioactive wastes safety, the crisis and nuclear materials management, the human and the environment protection, the international activities and cooperation, the quality insurance. It provides also information on the cooperation, the budget, the human resource policy and the communication activities. (A.L.B.)

Combustible structural composites and methods of forming combustible structural composites

Science.gov (United States)

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Rapport de frais de 2015-2016 pour Joanne Charette | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2015-2016 pour Joanne Charette. Total des frais de déplacement : CAD$47,347.81. Conférences pancanadiennes sur la transition démocratique avec le chercheur et coéditeur du livre. 30 mars 2016 au 3 avril 2016. CAD$1,981.78. Visite au Bureau régional de l'Asie. 26 février 2016 au 8 mars 2016.

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.

2017-03-28

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

Rapport de frais de 2017-2018 pour Margaret Biggs | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2017-2018 pour Margaret Biggs. Total des frais de déplacement : CAD$1,460.70. Participer au sommet du T20 sur les solutions mondiales. 29 mai 2017 au 31 mai 2017. CAD$852.39. Participer à un ...

Rapport de frais de 2017-2018 pour Mary Anne Chambers | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2017-2018 pour Mary Anne Chambers. Total des frais de déplacement : CAD$17,362.55. Réunion du Conseil des gouverneurs. 19 novembre 2017 au 24 novembre 2017. CAD$2,185.41. Réunions au CRDI 1 novembre 2017 CAD$714.15. Constatation de l'impact de la recherche en Afrique de l'Est.

Rapport de frais de 2017-2018 pour Uri Rosenthal | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2017-2018 pour Uri Rosenthal. Total des frais de déplacement : CAD$7,275.54. Réunion du Conseil des gouverneurs. 19 juin 2017 au 21 juin 2017. CAD$7,275.54. Ce que nous faisons · Financement ...

Rapport de frais de 2015-2016 pour Alanna Heath | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2015-2016 pour Alanna Heath. Total des frais de déplacement : CAD$912.20. Réunion du Conseil des gouverneurs. 13 juillet 2015 au 14 juillet 2015. CAD$912.20. Ce que nous faisons · Financement ...

IPSN activity report 1999; Rapport d'activite de l'IPSN 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The ''Institut de Protection et de Surete Nucleaire'' (IPSN), carries out researches and expert studies needed to manage nuclear risks and their consequences on people and environment. These activities cover the installation safety, the radioactive matter transport, the public health and environmental control, the nuclear matters safety and control and the crisis situation management. The IPSN have got also a mission of public information and participates to international actions in the domain of scientific researches or expert's report. This annual report presents the highlights of the year 1999, information on staff, budgets and geographical situation. Then technical and scientific papers gathers the activities of the year covered by the IPSN: the ''Free Tribune'', installations and radioactive wastes safety, crisis and nuclear matter management, public health and environment control, international cooperation. (A.L.B.)

Neutron noise in nuclear reactors; Le bruit neutronique des reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Blaquiere, A. [Institut National des Sciences et Techniques Nucleaires (France); Pachowska, R. [Universite Technique de Varsovie (Poland)

1961-06-15

The power of a nuclear reactor, in the operating conditions, presents fluctuations due to various causes. This random behaviour can be included in the study of 'noises'. Among other sources of noise, we analyse hereafter the fluctuations due: a) to the discontinuous emissions of neutrons from an independent source; b) to the multiplication of neutrons inside the reactor. The method which we present makes use of the analogies between the rules governing a nuclear reactor in operation and a number of radio-electrical systems, in particular the feed-back loops. The reactor can be characterized by its 'passing band' and is described as a system submitted to a sequence of random pulses. In non linear operating condition, the effect of neutron noise is defined by means of a non-linear functional, this theory is thus related to previous works the references of which are given at the end of the present report. This leads us in particular in the case of nuclear reactors to some results given by A. Blaquiere in the case of radio-electrical loops. (author) [French] La puissance d'un reacteur nucleaire, dans les conditions du regime, est affectee de fluctuations dont les causes sont tres diverses. Ce comportement aleatoire rentre dans le cadre general de l'etude des 'bruits'. Entre autres sources ce bruit, nous analysons ici les fluctuations dues: a) a l'emission discontinue des neutrons provenant d'une source autonome; b) a la multiplication des neutrons au sein du reacteur. La methode que nous introduisons exploite les analogies entre les lois qui regissent un reacteur nucleaire au regime et certains systemes radioelectriques, en particulier les circuits a boucle de reaction. Le reacteur est caracterise par sa 'bande passante' et est decrit comme un systeme soumis a une succession d'impulsions aleatoires. Dans les conditions de fonctionnement non lineaires, l'effet du bruit neutronique est precise en utilisant une fonctionnelle non lineaire, ce qui relie cette theorie a

Mesures de procédure spéciales et respect des droits de l'homme Rapport général

NARCIS (Netherlands)

Vervaele, J.A.E.

2009-01-01

Le but du rapport général est de mener une analyse comparative des rapports nationaux en vue de présenter les processus de transformation des systèmes de justice pénale internes, en particulier du procès pénal, étant donné que des mesures procédurales spéciales sont introduites pour appréhender le

IEA combustion agreement : a collaborative task on alternative fuels in combustion

International Nuclear Information System (INIS)

Larmi, M.

2009-01-01

The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

Rapport van het onderzoek naar de kosten, verbonden aan het bewaren van consumptie-aardappelen

NARCIS (Netherlands)

Anonymous,

1941-01-01

Het doel van deit rapport is vast te stellen hoe het verloop van den prijs van consumptie-aardappelen gedurende den winter en het voorjaar moet zijn om de gemaakte kosten en het verlies aan product goed te maken.

Internal combustion engine using premixed combustion of stratified charges

Science.gov (United States)

Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

2003-12-30

During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

Rapports 2016-2017 sur les frais de voyage pour Sophie d'Amours ...

International Development Research Centre (IDRC) Digital Library (Canada)

Beata Bialic

Date(s). 2016-07-06. Destination(s). Ottawa. Billet d'avion. 866.40 $. Frais de transport au sol ou autrement. 83.50 $. Frais de logement. 0.00 $. Repas et frais divers. 84.53 $. Autre frais. 0.00 $. Total. 1 034.43 $. Commentaires. Rapports 2016-2017 sur les frais de voyage pour Sophie d'Amours, gouverneur.

Combustion Stratification for Naphtha from CI Combustion to PPC

KAUST Repository

Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

2017-01-01

This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

Fuel and combustion stratification study of Partially Premixed Combustion

OpenAIRE

Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

2016-01-01

Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

Development of flameless combustion; Desarrollo de la combustion sin flama

Energy Technology Data Exchange (ETDEWEB)

Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

2010-11-15

The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

La responsabilité de protéger : Rapport de la Commission ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 janv. 2001 ... Ce qu'il est convenu d'appeler le « droit d'intervention humanitaire » est l'une des questions de politique internationale les plus controversées de la dernière décennie, que ce soit dans des situations où une intervention a eu lieu, comme au Kosovo, ou n'a pas eu lieu, comme au Rwanda. Dans son rapport ...

Rapport de frais de 2016-2017 pour Margaret Biggs | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2016-2017 pour Margaret Biggs. Total des frais de déplacement : CAD$6,727.48. Participation à la cérémonie de remise des prix Canada Gairdner 2016. 27 octobre 2016 au 28 octobre 2016. CAD$859.79. Assister à des réunions internes organisées par le CRDI. 9 septembre 2016 au 29 septembre ...

Rapport de frais de 2016-2017 pour Monte Solberg | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2016-2017 pour Monte Solberg. Total des frais de déplacement : CAD$4,369.35. Réunion du Conseil des gouverneurs. 20 juin 2016 au 22 juin 2016. CAD$1,996.51. Assister à des réunions internes organisées par le CRDI. 10 mai 2016 au 13 mai 2016. CAD$2,372.84. Ce que nous faisons ...

Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

Energy Technology Data Exchange (ETDEWEB)

Epinat, G. [APAVE Lyonnaise, 69 (France)

1996-12-31

After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

Rapport de frais de 2017-2018 pour Alanna Boyd | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2017-2018 pour Alanna Boyd. Total des frais de déplacement : CAD$1,493.41. Réunion du Conseil des gouverneurs. 21 novembre 2017 au 22 novembre 2017. CAD$907.21. Réunion du Conseil des gouverneurs. 20 juin 2017 au 21 juin 2017. CAD$586.20. Ce que nous faisons · Financement ...

Humor, Rapport, and Uncomfortable Moments in Interactions with Adults with Traumatic Brain Injury

Science.gov (United States)

Kovarsky, Dana; Schiemer, Christine; Murray, Allison

2011-01-01

We examined uncomfortable moments that damaged rapport during group interactions between college students in training to become speech-language pathologists and adults with traumatic brain injury. The students worked as staff in a community-based program affiliated with a university training program that functioned as a recreational gathering…

Neuro-Linguistic Programming: Improving Rapport between Track/Cross Country Coaches and Significant Others

Science.gov (United States)

Helm, David Jay

2017-01-01

This study examines the background information and the components of N.L.P., being eye movements, use of predicates, and posturing, as they apply to improving rapport and empathy between track/cross country coaches and their significant others in the arena of competition to help alleviate the inherent stressors.

Combustion stratification for naphtha from CI combustion to PPC

NARCIS (Netherlands)

Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

2017-01-01

This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

Low NOx combustion technologies for high-temperature natural gas combustion

International Nuclear Information System (INIS)

Flamme, Michael

1999-01-01

Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

Combustion instability control in the model of combustion chamber

International Nuclear Information System (INIS)

Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

2013-01-01

An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

Om SIDAs rapport: "Towards an urban world - urbanization and development assistance"

DEFF Research Database (Denmark)

Eskemose Andersen, Jørgen

1996-01-01

Byerne i ulandene har et dårligt ry. De er centre for prostitution, kriminalitet og arbejdsløshed. Befolkningerne lever i armod i elendige endeløse slumområder uden udsigt til forbedrede levevilkår. Byernes infrastruktur er mangelfuld, nedslidt og fungere stort set kun i de nedarvede koloniale de...... udkommet rapport: Towards an Urban World af den svenske bistandsorganisation Sida.   Udgivelsesdato: 1996...

Indicateurs de mobilité durable : de l'état de l'art à la définition des indicateurs dans le projet Simbad. Rapport intermédiaire n°2

OpenAIRE

Verry , Damien; Nicolas , Jean-Pierre

2005-01-01

Rapport pour le compte de la DRAST (Ministère de l'Équipement) et de l'ADEME dans le cadre du groupe 11 du PREDIT. 96 p.Voir aussi :- le Rapport intermédiaire n°1"Modèles d'interaction entre transport et urbanisme : état de l'art et choix du modèle pour le projet SIMBAD". http://halshs.ccsd.cnrs.fr/halshs-00101342- le Rapport intermédiaire n°4"L'architecture du modèle au sein du projet SIMBAD."http://halshs.ccsd.cnrs.fr/halshs-00101399; Rapport de recherche; Le projet SIMBAD (SImuler les MoBi...

Rotary combustion device

NARCIS (Netherlands)

2008-01-01

Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

Measurement of the C / H ratio using neutrons; Mesure du rapport C / H au moyen des neutrons

Energy Technology Data Exchange (ETDEWEB)

Martinelli, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Ricci, H [Universite de Lima (Peru)

1960-07-01

A probe made up of a Ra ({alpha}, n) Be neutron source and a proportional counter filled with boron trifluoride has been used to measure the C/H ratio in hydrocarbons. The intensity of the thermal neutron flux in the neighbourhood of the detector increases with the concentration of the hydrocarbon hydrogen surrounding it. By measuring the density it is possible to deduce the C/H ratio. It is thus possible to evaluate the C/H ratio with a precision equal to that given by the {beta}-ray transmission method. The errors arising from the chemical nature of the hydrocarbon can be reduced to a minimum. This method has the advantage of allowing the measurement of the C/H ratio of hydrocarbons contained in recipients or thick steel tubing by means an independent portable apparatus. (author) [French] Une sonde constituee d'une source de neutrons Ra ({alpha}, n) Be et d'un compteur proportionnel a remplissage de trifluorure de bore a ete utilisee pour mesurer le rapport C/H dans les hydrocarbures. Le flux des neutrons thermiques au voisinage du detecteur est d'autant plus intense que la concentration en hydrogene de l'hydrocarbure qui entoure la sonde est plus elevee. Une mesure de densite permet d'en deduire le rapport C/H. On peut ainsi evaluer le rapport C/H avec une precision aussi bonne que celle que l'on obtient par transmission de rayons {beta}. Les erreurs provenant de la nature chimique de l'hydrocarbure peuvent etre minimisees. Cette methode presente l'avantage de permettre la mesure du rapport C/H d'hydrocarbures contenus dans des recipients ou des canalisations epaisses en acier a l'aide d'un appareil exterieur transportable. (auteur)

Rapports 2016-2017 sur les frais de voyage pour Sophie d'Amours ...

International Development Research Centre (IDRC) Digital Library (Canada)

chantal taylor

But: Réunion du Conseil des gouverneurs. Date(s). 2016-11-21 à 2016-11-23. Destination(s). Ottawa. Billet d'avion. 350.81 $. Frais de transport au sol ou autrement. 61.61 $. Frais de logement. 590.10 $. Repas et frais divers. 172.79 $. Autre frais. 0.00 $. Total. 1 175.31 $. Commentaires. Rapports 2016-2017 sur les frais ...

Rapport de frais de 2015-2016 pour Nadir Patel | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

Accueil · À propos du CRDI · Obligation de rendre compte · Transparence · Déplacements et accueil. Rapport de frais de 2015-2016 pour Nadir Patel. Total des frais de déplacement : CAD$13,745.04. Réunion du Conseil des gouverneurs. 20 mars 2016 au 22 mars 2016. CAD$7,750.97. Réunion du Conseil des ...

Integrating Rapport-Building into Language Instruction: A Study of Korean Foreign Language Classes

Science.gov (United States)

Park, Mi Yung

2016-01-01

Using a conversation-analytic approach along with the notions of frame and footing (Goffman 1981), this study examines what strategies teachers use to build rapport with their students in Korean as a foreign language classrooms. It also discusses what kinds of interactional resources they employ in tandem with these strategies. Analysis of…

Combustion physics

Science.gov (United States)

Jones, A. R.

1985-11-01

Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

Rapport: Coding Class - Dokumentation og evaluering

DEFF Research Database (Denmark)

Hansbøl, Mikala; Ejsing-Duun, Stine

2017-01-01

Denne rapport rummer evaluering og dokumentation af Coding Class projektet . Coding Class projektet blev igangsat i skoleåret 2016/2017 af IT-Branchen i samarbejde med en række medlemsvirksomheder, Københavns kommune, Vejle Kommune, Styrelsen for IT- og Læring (STIL) og den frivillige forening...... Coding Pirates . Rapporten er forfattet af Docent i digitale læringsressourcer og faglig leder af forsknings- og udviklingsmiljøet Digitalisering i Skolen (DiS), Mikala Hansbøl, fra Institut for Skole og Læring ved professionshøjskolen Metropol; og Lektor i læringsteknologi, interaktionsdesign, design...... tænkning og design-pædagogik, Stine Ejsing-Duun fra Forskningslab: It og Læringsdesign (ILD-LAB) ved Institut for Kommunikation ved Aalborg Universitet i København. Vi har fulgt og gennemført evaluering og dokumentation af Coding Class projektet i perioden november 2016 til maj 2017...

Direct interaction in nuclear reactions: a theory; L'interaction directe dans les reactions nucleaires: theorie

Energy Technology Data Exchange (ETDEWEB)

Dominicis, C.T. de [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

General treatment of the foundations of direct interaction in nuclear reactions; representation of the instantaneous elastic scattering amplitude by the scattering amplitude due to a complex potential; expansion of the instantaneous inelastic scattering amplitude and discussion of the 1. Bohr approximation (distorted waves) contribution to individual and collective states of excitation. (author) [French] Expose general sur les fondements de l'interaction directe dans les reactions nucleaires; representation de l'amplitude de diffusion instantanee elastique par celle due a un potentiel complexe; developpement de l'amplitude de diffusion instantanee inelastique et discussion de la contribution de la premiere approximation de Bohr (sur des distendues) a l'excitation d'etats individuels et collectifs. (auteur)

Le rapport Coopération pour le développement de l'OCDE souligne ...

International Development Research Centre (IDRC) Digital Library (Canada)

14 févr. 2018 ... Source: Rapport Coopération pour le développement 2017 de l'OCDE ... des nouvelles sources de données et des nouveaux types de données qui ... constituent quelques-unes des nouvelles sources d'information qui offrent ...

Oriëntasiebehoeftes en agendabepaling van mediafigure by vrouelesers van Rapport

OpenAIRE

2014-01-01

M.A. (Communication Studies) To firstly formulate, from the literary review, an integrated model which describes the mass communication process. Specifically the relationship between orientation needs, media usage and agenda-setting in the broader context of the individual, the media, and society. The model was delineated to define the woman as individual, Rapport as medium, and orientation needs and agenda-setting in terms of media figures. The second aim was to conduct an empirical inves...

Condition féminine, rapports sociaux de sexe, genre…

OpenAIRE

Zancarini-Fournel, Michelle

2012-01-01

L’article se propose de retracer brièvement l’itinéraire et le fondement théorique (du marxisme au poststructuralisme) des termes « condition féminine », « rapports sociaux de sexe » et « genre » dans différentes disciplines (sociologie, histoire et science politique) en précisant la chronologie différenciée de leur usage en France et dans le monde anglophone. The article considers the trajectory and theoretical foundations (from Marxism to post-structuralism) of a number of terms: “femini...

Some Factors Affecting Combustion in an Internal-Combustion Engine

Science.gov (United States)

Rothrock, A M; Cohn, Mildred

1936-01-01

An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

Reduced NOX combustion method

International Nuclear Information System (INIS)

Delano, M.A.

1991-01-01

This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

Rapport de frais de 2016-2017 pour John McArthur | CRDI - Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

Rapport de frais de 2016-2017 pour John McArthur. Total des frais de déplacement : CAD$6,102.11. Réunion du Conseil des gouverneurs. 20 mars 2017 au 22 mars 2017. CAD$1,288.38. Réunion du Conseil des gouverneurs. 21 novembre 2016 au 23 novembre 2016. CAD$1,265.87. Réunion du comité ad hoc 31 ...

Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

Science.gov (United States)

Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

2008-10-07

This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

Who Is Controlling the Interaction? The Effect of Nonverbal Mirroring on Teacher-Student Rapport

Science.gov (United States)

Jiang-yuan, Zhou; Wei, Guo

2012-01-01

This study investigated the effect of nonverbal mirroring on teacher-student rapport in one-on-one interactions. Nonverbal mirroring refers to the unconscious mimicry of the postures, mannerisms, facial expressions, and other behaviors of one's interaction partner in social interactions. In a within-subjects paradigm, students had four…

Rapport annuel au Parlement Loi sur l'accès à l'information Centre ...

International Development Research Centre (IDRC) Digital Library (Canada)

leonardi

accès à l'information. Source. Nombre de demandes. 0. Médias. 1. Rapport statistique sur la Loi sur l'accès à l'information. Nom de l'institution : Centre de recherches pour le développement international. Période visée par le ...

2015-2016 Rapports sur les frais de voyage et d'accueil pour Scott ...

International Development Research Centre (IDRC) Digital Library (Canada)

Ruxandra Staicu

Réunion du Conseil des gouverneurs. Date(s):. 2015-07-13 à 2015-07-14. Destination(s):. Ottawa. Billet d'avion: Frais de transport au sol ou autrement: 31.46 $. Frais de logement: Repas et frais divers: Autre frais: Total: 31.46 $. Commentaires: 2015-2016 Rapports sur les frais de voyage et d'accueil pour Scott Gilmore, ...

The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

Energy Technology Data Exchange (ETDEWEB)

C. M. Pancerella; L. A. Rahn; C. Yang

2000-02-01

The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

Simulations of a Circulating Fluidized Bed Chemical Looping Combustion System Utilizing Gaseous Fuel Simulation de la combustion en boucle chimique d’une charge gazeuse dans un lit fluidisé circulant

Directory of Open Access Journals (Sweden)

Mahalatkar K.

2011-05-01

Full Text Available Numerical studies using Computational Fluid Dynamics (CFD have been carried out for a complete circulating fluidized bed chemical looping combustor described in the literature (Abad et al., 2006 Fuel 85, 1174-1185. There have been extensive experimental studies in Chemical Looping Combustion (CLC, however CFD simulations of this concept are quite limited. The CLC experiments that were simulated used methane as fuel. A 2-D continuum model was used to describe both the gas and solid phases. Detailed sub-models to account for fluid-particle and particleparticle interaction forces were included. Global models of fuel and carrier chemistry were utilized. The results obtained from CFD were compared with experimental outlet species concentrations, solid circulation rates, solid mass distribution in the reactors, and leakage and dilution rates. The transient CFD simulations provided a reasonable match with the reported experimental data. Des études numériques de simulation des écoulements (CFD ont été réalisées sur un lit fluidisé circulant opérant en combustion par boucle chimique (CLC décrit dans la littérature (Abad et al., 2006 Fuel 85, 1174-1185. Si de nombreuses études expérimentales ont été conduites pour étudier le procédé CLC, les études concernant la simulation des écoulements par CFD de ce concept sont très limitées. Le système de combustion en boucle chimique simulé dans cette étude concerne la combustion d’une charge gazeuse (méthane. Un modèle 2-D à deux phases continues a été utilisé pour décrire les phases gaz et solide avec des sous-modèles détaillés pour décrire les forces d’interactions entre fluideparticule et particule-particule. Des modèles cinétiques globaux ont été intégrés pour décrire les réactions de combustion et de transformation du matériau transporteur d’oxygène. Les résultats obtenus par CFD ont été comparés aux concentrations expérimentales mesurées des diff

New class of combustion processes

International Nuclear Information System (INIS)

Merzhanov, A.G.; Borovinskaya, I.P.

1975-01-01

A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

Experimental validation for combustion analysis of GOTHIC code in 2-dimensional combustion chamber

International Nuclear Information System (INIS)

Lee, J. W.; Yang, S. Y.; Park, K. C.; Jung, S. H.

2002-01-01

In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. The experimental chamber has about 24 liter free volume (1x0.024x1 m 3 ) and 2-dimensional rectangular shape. The test were preformed with 10% hydrogen/air gas mixture and conducted with combination of two igniter positions (top center, top corner) and two boundary conditions (bottom full open, bottom right half open). Using the lumped parameter and mechanistic combustion model in GOTHIC code, the SNU experiments were simulated under the same conditions. The GOTHIC code prediction of the hydrogen combustion phenomena did not compare well with the experimental results. In case of lumped parameter simulation, the combustion time was predicted appropriately. But any other local information related combustion phenomena could not be obtained. In case of mechanistic combustion analysis, the physical combustion phenomena of gas mixture were not matched experimental ones. In boundary open cases, the GOTHIC predicted very long combustion time and the flame front propagation could not simulate appropriately. Though GOTHIC showed flame propagation phenomenon in adiabatic calculation, the induction time of combustion was still very long compare with experimental results. Also, it was found that the combustion model of GOTHIC code had some weak points in low concentration of hydrogen combustion simulation

Publication du rapport de BSR sur le travail des enfants en Birmanie ...

International Development Research Centre (IDRC) Digital Library (Canada)

22 juin 2016 ... Le rapport, intitulé « Child Labor in Myanmar's Garment Sector », a été préparé par Business for Social Responsibility (BSR). Il arrive à point nommé, car les intervenants du monde des affaires sur la scène internationale manifestent un intérêt croissant à l'égard du Myanmar, parallèlement à la levée des ...

A Survey of the Fuel Cycles Operated in the United Kingdom; Etude d'ensemble sur les cycles de combustible au Royaume-Uni; Obzor toplivnykh tsiklov, ispol'zuemykh v soedinennom korolevstve; Estudio de los ciclos de combustible utilizados en el Reino Unido

Energy Technology Data Exchange (ETDEWEB)

Allday, C. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

1963-10-15

son programme d'energie d'origine nucleaire sur la filie re des reacteurs a l'uranium naturel et au graphite, refroidis par un gaz. Les reacteurs de Calder Hall et de Chapelcross fonctionnent depuis sept ans; ceux de Berkeley et de Bradwell, qui dependent du Central Electricity Generating Board (CEGB), sont maintenant en service et sept autres reacteurs sont en construction ou en projet. Le combustible destine a ces reacteurs est etudie et fabrique dans l'usine de l'Atomic Energy Authority (AEA) a Springfields, puis transporte jusqu'au reacteur. Apres irradiation et dechargement, le combustible est transporte a l'usine de l'AEA, situee a Windscale, ou l'uranium et le plutonium sont separes des produits de fission. L'auteur decrit l'experience britannique en matiere d'etude et de fabrication du combustible, d'exploitation du reacteur, de transport et de traitement chimique du combustible irradie. Il examine brievement le comportement du combustible dans le reacteur et les differents programmes possibles de chargement et de dechargement, ce sujet etant developpe dans un autre memoire. b) Reacteurs utilisant les combustibles enrichis. Le Royaume-Uni met au point un reacteur perfectionne refroidi par un gaz (Advanced Gas Cooled Reactor = AGR), dont le prototype a ete mis en service en 1963. Le combustible est fabrique a partir d'oxyde d'uranium enrichi gaine d' acier inoxydable; apres irradiation, il sera traite dans une novelle installation qui sera ajoutee a l'usine de separation de Windscale ou est actu ellement traite le combustible gaine de magnox. L'uranium enrichi destine a AGR est produit par l'usine de diffusion situee a Capenhurst. L'oxyde d'uranium naturel enrichi au plutonium peut remplacer, comme combustible, l'oxyde d'uranium enrichi. L'auteur decrit l'experience acquise dans la transformation de l'oxyde destine a AGR et dans le fonctionnement du reacteur et indique comment on envisage de traiter le combustible irradie. Il examine le cas de l'utilisation d

Preliminary assessment of combustion modes for internal combustion wave rotors

Science.gov (United States)

Nalim, M. Razi

1995-01-01

Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

De nouveaux mécanismes de résilience : rapport interactif au sujet ...

International Development Research Centre (IDRC) Digital Library (Canada)

13 nov. 2012 ... On y trouve de nombreux liens vers des ressources relatives au programme et aux projets, ainsi que des pistes pour explorer plus en profondeur les résultats des recherches scientifiques. Lire le rapport De nouveaux mécanismes de résilience (PDF, 2,98 Mo). Une version récente d'Adobe Reader est ...

Awareness of households to the development of wind energy sites - Reporting on a survey; Receptivite des menages au developpement des sites eoliens. Rapport d'enquete

Energy Technology Data Exchange (ETDEWEB)

Voisard, M

2000-07-01

This report for the Swiss Federal Office of Energy presents in tables and diagrams the results of a survey involving 421 households in Switzerland, about their awareness to energy issues and, in particular, to all what regards wind energy and wind power plants. Globally, 80% of the persons asked for their opinion believe that electric power demand will continue to increase. 66% of them are in favour of increased use of renewable energy sources and would consequently agree with a 10% more expensive end-user energy price. 89% of the persons taking part to the survey approve the installation of wind energy farms in Switzerland. Moreover, statistics indicates that the households living in regions already equipped with wind farms are significantly more favorable to the creation of new wind energy sites than those not living in these regions. By the end of the day, it turns out that the main reasons for accepting wind energy are environmental concerns as well as the fear of being obliged to use nuclear power. [French] Ce rapport presente par des graphiques et des tableaux le resultat d'un sondage d'opinion aupres de 421 menages en Suisse, sur la sensibilite du public aux problemes de l'energie et plus particulierement sur sa perception de tout ce qui concerne l'energie du vent et son exploitation par l'implantation d'eoliennes. Globalement, 80% des menages pensent que la demande d'energie electrique va poursuivre sa croissance. 66% d'entre eux sont favorables au developpement des energies renouvelables et prets a accepter en consequence une augmentation du prix de l'energie allant jusqu'a 10%. 89% des personnes interrogees sont favorables au developpement des eoliennes en Suisse. De plus, la statistique montre de maniere significative que les menages des regions dans lesquelles sont deja implantes des sites eoliens sont plus favorables au developpement des eoliennes que les autres. Finalement, le respect de l'environnement et la crainte d'avoir a recourir a l

Description of computer code PRINS, Program for Interpreting Gamma Spectra, developed at ENEA

Energy Technology Data Exchange (ETDEWEB)

Borsari, R. [ENEA, Centro Ricerche `E. Clementel`, Bologna (Italy). Dip. Energia

1995-11-01

The computer code PRINS, program for interpreting gamma Spectra, has been developed in collaboration with CENG/SECC (Centre Etude Nucleaire Grenoble / Service Etude Comportement du Combustible). Later it has been updated and improved at ENEA. Properties of the PRINS code are: (1) A powerful algorithm to locate the peaks; (2) An accurate evaluation of the errors; (3) Possibility of an automatic channels-energy calibration.

Description of computer code PRINS, Program for Interpreting Gamma Spectra, developed at ENEA

International Nuclear Information System (INIS)

Borsari, R.

1995-12-01

The computer code PRINS, PRogram for INterpreting gamma Spectra, has been developed in collaboration with CENG/SECC (Centre Etude Nucleaire Grenoble / Service Etude Comportement du Combustible). Later it has been updated and improved at ENEA. Properties of the PRINS code are: I) A powerful algorithm to locate the peaks; 2) An accurate evaluation of the errors; 3) Possibility of an automatic channels-energy calibration

Study of a device for the direct measurement of the fission gas pressure inside an in-pile fuel element; Etude d'un dispositif pour la mesure directe de la pression des gaz de fission a l'interieur d'un element combustible en pile

Energy Technology Data Exchange (ETDEWEB)

Lavaud, B; Uschanoff, S [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The fission gas pressure inside a fuel element made of a refractory fuel constitutes an important limiting factor for the burn-up. Although it is possible to calculate approximately the volume of gas produced outside the fuel during its life-time; it is nevertheless very difficult to evaluate the pressure since the volume allowed to the fission gases, as well as their temperature are known only very approximately. This physical value, which is essential for the technologist, can only be known by direct in-pile measurement of the pressure. The report describes the equipment which has been developed for this test. (authors) [French] La pression des gaz de fission a l'interieur d'un element combustible a combustible refractaire constitue une des limitations importantes du taux de combustion. Si on peut approcher par calcul la determination du volume, des gaz degages hors du combustible au cours de sa vie, il est par contre tres difficile d'evaluer la pression car le volume alloue aux gaz de fission et leur temperature sont tres mal connus. Cette donnee essentielle pour le technologue ne peut etre atteinte que par une mesure directe en pile de la pression. Le rapport decrit l'appareillage qui a ete mis au point pour cet essai. (auteurs)

L’ANALYSE DU DISCOURS DE LA RESPONSABILITE SOCIALE DE L’ENTREPRISE A TRAVERS LES RAPPORTS ANNUELS DE DEVELOPPEMENT DURABLE D’ ENTREPRISES FRANÇAISES DU CAC 40

Directory of Open Access Journals (Sweden)

Jacques IGALENS

2006-01-01

Full Text Available Sous la pression des parties prenantes, le nombre de rapports dedéveloppement durable ne cesse d'augmenter. Jusqu'ici les méthodesd'analyse des informations qu'ils contiennent sont essentiellementcomptables. L'enjeu de ces rapports va au-delà des indicateurs chiffrésfournis par exemple par la GRI, Global Reporting Initiative. Il s'agit pour uneentreprise de légitimer son action et les conséquences de son action dansles domaines sociaux, environnementaux et societaux. La place tenue par lediscours dans ces rapports est essentielle et la méthode proposée dans cetarticle est ainsi celle de "l'analyse des discours" notamment en s'appuyantsur les caractéristiques de l'énonciation et sur celles des procédésrhétoriques. Ainsi apparaît que les entreprises ne se contentent pas de "faireun rapport" mais qu'elles essaient de construire un monde, un monde danslequel elles se présentent en héros positif, un monde dont elles définissentles règles.

Combustion modeling in internal combustion engines

Science.gov (United States)

Zeleznik, F. J.

1976-01-01

The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

A predictive model of natural gas mixture combustion in internal combustion engines

Directory of Open Access Journals (Sweden)

Henry Espinoza

2007-05-01

Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

Boiler using combustible fluid

Science.gov (United States)

Baumgartner, H.; Meier, J.G.

1974-07-03

A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

Ignition et oxydation des particules de combustible solide pulvérisé Ignition and Oxidation of Pulverized Solid Fuel

Directory of Open Access Journals (Sweden)

De Soete G. G.

2006-11-01

élais d'ignition ont été déterminés pour un grand nombre de combustibles solides de rang inférieur et supérieur (charbons, cokes, asphaltènes, suies, bois, graphite. L'étude de la vitesse expérimentale de la combustion hétérogène, notamment l'étude de la température apparente d'activation, et sa dépendance par rapport à la taille des particules et à la concentration d'oxygène, montre que, dans les conditions des essais, cette combustion est contrôlée par la désorption du CO et se déroule principalement en régime cinético-diffusionnel mixte. L'étude de la dépendance des délais d'ignition par rapport à la température, la taille des particules et la pression partielle d'oxygène, suggère que, pendant ces délais, les réactions se déroulent en régime cinétique pur et que le produit des réactions de désorption est principalement le CO. The heated-grid method is used to investigate the competition between (1 the devolatilization and subsequent oxidation of pyrolysis products and (2 the ignition of the solid matrix and its rapid combustion. A comparison between the instant of ignition and the start of pyrolysis is used to determine the range in which ignition of a pyrolyzable solid fuel of the whole coal ignitiontype (i. e. when ignition occurs before pyrolysis becomes measurable occurs as a function of temperature, particle size and oxygen concentration. The results suggest that this type of ignition might occur, as a general rule, under conditions involving pulverized solid fuels in industrial flames. In the case of whole coalignition, the rate of combustion of the solid matrix is inhibited during the period following ignition. This inhibition is due partly to the difficulty oxygen has of spreading through the pores during the discharge of pyrolysis products and partly to preferential oxygen consumption during the oxidation of pyrolysis products, mainly when this oxidation develops in the form of flames. t is only when pyrolysis ends that

HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

Energy Technology Data Exchange (ETDEWEB)

Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

2004-07-01

This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

1990-10-01

Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

Rapport over een inventarisatie van- en een studie over de entomofauna van het C.R.M. reservaat Broekhuizen

NARCIS (Netherlands)

Peerdeman, M.P.

1976-01-01

Inventarisatie van het terrein rondom het kasteel te Broekhuizen/Leersum. De inventarisatie werd hoofdzakelijk gericht op de entomofauna, maar in dit rapport zijn ook enkele gegevens over andere diergroepen opgenomen.

Life scientists in the nuclear domain

International Nuclear Information System (INIS)

Guetat, Philippe; Egal, Yves; Wolf, Gerard; Fleuriot, Sabine; Van Hecke, Walter; Coulon, Remi; Seilhean-Frossard, Estelle; Sevin, Helene; Schoulz, Daniel; Lebaron-Jacobs, Laurence; Menetrier, Florence; Crochon, Philippe; Buchholzer, Vincent; Chagvardieff, Pierre; Camus, Henri; Raynaud, Jacques; Biet, Elodie; Mathis, Paul

2011-01-01

This dossier is made of several small articles entitled: - 'Exploite intelligemment, le nucleaire n'est pas dangereux' (Exploited smartly, nuclear is not dangerous); - 'l'amont du cycle du combustible nucleaire' (the upstream part of the nuclear fuel cycle); - 'Le nucleaire, une energie recyclable' (Nuclear, a recyclable energy); - 'Centrale nucleaire et environnement - exemple de Cattenom' (Nuclear power station and the environment - the example of Cattenom); - 'Ingenieur environnement, un metier exigeant' (Engineer in environment, a demanding profession); - 'Rayonnements ionisants: a quels risques sommes-nous exposes?' (Ionizing radiations: to which risks are we exposed?); - 'Les anciennes mines d'uranium, un sujet toujours d'actualite' (Old uranium mines: a topic always of actuality); - 'Les dechets nucleaires, des dechets comme les autres?' (Nuclear wastes: wastes like others?); - 'Les Ingenieurs du Vivant dans le nucleaire' (Engineers in life sciences in the nuclear sector); - 'Tchernobyl: 25 ans apres, quel impact sur la sante?' (Chernobyl: 25 years after: which impact on health?); - 'Fukushima, catastrophe naturelle ou accident nucleaire?' (Fukushima, natural disaster or nuclear accident?); - 'Rehabiliter les sols contamines' (Restoring contaminated soils); - 'Nucleaire et risque de proliferation' (nuclear and risk of proliferation); - 'Les rayonnements dans la lutte contre le cancer' (Radiations in the struggle against cancer); - 'L'energie nucleaire est-elle essentielle a notre bouquet energetique?' (Is nuclear energy essential to our energy mix?). The articles of this dossier outline that nuclear energy can be exploited without any danger if it is done intelligently, describes the upstream part of the nuclear fuel cycle, outlines that most of the nuclear fuel can be recycled, presents the activities of survey and control of the environment around a French nuclear power station, outlines the high commitment required for and engineer in environment working

The fuel element of the first charge for EL 4; presentation, main problems arising in the research, production problems; L'element combustible du 1. jeu de EL 4; presentation, problemes essentiels poses par l'etude, problemes de fabrication

Energy Technology Data Exchange (ETDEWEB)

Ringot, C; Bailly, H; Bujas, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The fuel element making up the first charge for EL-4 is made of slightly enriched uranium oxide canned in stainless steel. This fuel element makes it possible to operate the reactor in the safest conditions awaiting the development of the fuel which will be finally adopted; this will have a low absorption can: beryllium, or a zirconium copper alloy. The 500 mm assembly is made up of 19 small rods placed on 3 rings, inside a graphite jacket. The solution adopted was a solution using completely independent small rods. This report deals with possible problems resulting from their study and production. (authors) [French] L'element combustible du 1er jeu EL-4 est un element combustible a oxyde d'uranium legerement enrichi gaine d'acier inoxydable. C'est un element combustible permettant de faire fonctionner le reacteur EL 4 dans des conditions aussi sures que possible avant de mettre au point le combustible definitif qui sera a gaine peu absorbante: beryllium, ou alliage zirconium-cuivre. L'assemblage de longueur 500 mm est constitue de 19 crayons places sur 3 couronnes, a l'interieur d'une chemise de graphite. La solution adoptee a ete une solution a crayons independants les uns des autres. Ce rapport traite des problemes eventuels poses par leur etude et leur fabrication. (auteurs)

Activation analysis using {gamma} photons; Analyse par activation aux photons {gamma}

Energy Technology Data Exchange (ETDEWEB)

Engelmann, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1967-07-01

This report summarizes all the data required for using photonuclear reactions in the field of analysis. After a brief review of the elementary properties of nuclear reactions induced by photon irradiation, the main characteristics are given of high energy (E > 20 MeV) Bremsstrahlung sources. The principle of activation analysis based on the use of photons is given. Actual examples of the analytic possibilities are described in detail, in particular in the case of the determination of very small quantities (< 10{sup -6}) of C, N, O and F. The influence of interfering nuclear reactions is discussed. (author) [French] Ce rapport se propose de resumer l'ensemble des connaissances indispensables pour l'utilisation des reactions photonucleaires a des fins analytiques. Apres quelques rappels concernant les proprietes elementaires des reactions nucleaires induites par irradiation dans les photons, les principales caracteristiques des sources de rayonnement de freinage de haute energie (E > 20 MeV)| sont donnees. Le principe de l'analyse par activation aux photons est rappele. Des exemples concrets sur les possibilites analytiques sont developpes, particulierement en ce qui concerne la determination de quantites tres faibles (< 10{sup -6}) de C, N, O et F. L'influence des reactions nucleaires parasites est discutee. (auteur)

Uncertainties in hydrogen combustion

International Nuclear Information System (INIS)

Stamps, D.W.; Wong, C.C.; Nelson, L.S.

1988-01-01

Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

Science.gov (United States)

Firmansyah; Aziz, A. R. A.; Heikal, M. R.

2015-12-01

The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

Science.gov (United States)

Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

2016-05-01

Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

When students from different professions are co-located: the importance of interprofessional rapport for learning to work together.

Science.gov (United States)

Croker, Anne; Fisher, Karin; Smith, Tony

2015-01-01

With increasing interest and research into interprofessional learning, there is scope to more deeply understand what happens when students from different professions live and study in the same location. This study aimed to explore the issue of co-location and its effects on how students learn to work with other professions. The setting for this study was a rural health education facility in Australia with close links to local health care and community services. Philosophical hermeneutics informed the research method. Interviews were undertaken with 29 participants, including students, academic educators and clinical supervisors in diagnostic radiography, medicine, nursing, nutrition and dietetics, pharmacy, physiotherapy, occupational therapy, and speech pathology. Photo-elicitation was used to facilitate participant engagement with the topic. The findings foreground the value of interprofessional rapport building opportunities for students learning to work together. Enabled by the proximity of different professions in shared educational, clinical and social spaces, interprofessional rapport building was contingent on contextual conditions (balance of professions, shared spaces and adequate time) and individual's interpersonal capabilities (being interested, being inclusive, developing interpersonal bonds, giving and receiving respect, bringing a sense of own profession and being patient-centred). In the absence of these conditions and capabilities, negative professional stereotypes may be inadvertently re-enforced. From these findings suggestions are made for nurturing interprofessional rapport building opportunities to enable students of different professions to learn to work together.

IPSN activity report 1999; Rapport d'activite de l'IPSN 1999

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-07-01

The ''Institut de Protection et de Surete Nucleaire'' (IPSN), carries out researches and expert studies needed to manage nuclear risks and their consequences on people and environment. These activities cover the installation safety, the radioactive matter transport, the public health and environmental control, the nuclear matters safety and control and the crisis situation management. The IPSN have got also a mission of public information and participates to international actions in the domain of scientific researches or expert's report. This annual report presents the highlights of the year 1999, information on staff, budgets and geographical situation. Then technical and scientific papers gathers the activities of the year covered by the IPSN: the ''Free Tribune'', installations and radioactive wastes safety, crisis and nuclear matter management, public health and environment control, international cooperation. (A.L.B.)

Safety report concerning the reactor Pegase - volume 1 - Description of the installation - volume 2 - Safety of the installations; Rapport de surete du reacteur pegase - tome 1 - Description des installations - tome 2 - Surete des installations

Energy Technology Data Exchange (ETDEWEB)

Lacour, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Legoin, P. [S.E.M. Hispano-Suiza, 92 - Colombes (France)

1964-07-01

In the first volume: This report is a description of the reactor Pegase, given with a view to examine the safety of the installations. The Cadarache site at which they are situated is briefly described, in particular because of the consequences on the techniques employed for building Pegase. A description is also given of the original aspects of the reactor. The independent loops which are designed for full-scale testing of fuel elements used in natural uranium-gas-graphite reactor systems are described in this report, together with their operational and control equipment. In the second volume: In the present report are examined the accidents which could cause damage to the Pegase reactor installation. Among possible causes of accidents considered are the seismicity of the region, an excessive power excursion of the reactor and a fracture in the sealing of an independent loop. Although all possible precautions have been taken to offset the effects of such accidents, their ultimate consequences are considered here. The importance is stressed of the security action and regulations which, added to the precautions taken for the construction, ensure the safety of the installations. (authors) [French] Dans le volume 1: Ce rapport est une description du reacteur Pegase, afin d'examiner la surete des installations. Le site de CADARACHE ou elles sont situees, a ete sommairement decrit, en particulier, a cause des consequences sur les techniques mises en oeuvre pour la realisation de Pegase. Nous nous sommes egalement attache a decrire les aspects originaux du reacteur. Les boucles autonomes destinees a tester en vraie grandeur des elements combustibles de la filiere uranium naturel graphite-gaz, ainsi que leurs dispositifs de controle et d'exploitation, figurent egalement dans ce rapport. Dans le volume 2: Dans le present rapport, nous examinons des accidents pouvant endommager des installations du reacteur Pegase. Les origines d'accidents examines

Safety report concerning the reactor Pegase - volume 1 - Description of the installation - volume 2 - Safety of the installations; Rapport de surete du reacteur pegase - tome 1 - Description des installations - tome 2 - Surete des installations

Energy Technology Data Exchange (ETDEWEB)

Lacour, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Legoin, P [S.E.M. Hispano-Suiza, 92 - Colombes (France)

1964-07-01

In the first volume: This report is a description of the reactor Pegase, given with a view to examine the safety of the installations. The Cadarache site at which they are situated is briefly described, in particular because of the consequences on the techniques employed for building Pegase. A description is also given of the original aspects of the reactor. The independent loops which are designed for full-scale testing of fuel elements used in natural uranium-gas-graphite reactor systems are described in this report, together with their operational and control equipment. In the second volume: In the present report are examined the accidents which could cause damage to the Pegase reactor installation. Among possible causes of accidents considered are the seismicity of the region, an excessive power excursion of the reactor and a fracture in the sealing of an independent loop. Although all possible precautions have been taken to offset the effects of such accidents, their ultimate consequences are considered here. The importance is stressed of the security action and regulations which, added to the precautions taken for the construction, ensure the safety of the installations. (authors) [French] Dans le volume 1: Ce rapport est une description du reacteur Pegase, afin d'examiner la surete des installations. Le site de CADARACHE ou elles sont situees, a ete sommairement decrit, en particulier, a cause des consequences sur les techniques mises en oeuvre pour la realisation de Pegase. Nous nous sommes egalement attache a decrire les aspects originaux du reacteur. Les boucles autonomes destinees a tester en vraie grandeur des elements combustibles de la filiere uranium naturel graphite-gaz, ainsi que leurs dispositifs de controle et d'exploitation, figurent egalement dans ce rapport. Dans le volume 2: Dans le present rapport, nous examinons des accidents pouvant endommager des installations du reacteur Pegase. Les origines d'accidents examines comprennent la seismicite

Contribution to the study of the fission-gas release in metallic nuclear fuels; Contribution a l'etude du degagement des gaz de fission dans les combustibles nucleaires metalliques

Energy Technology Data Exchange (ETDEWEB)

Kryger, B [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-10-01

In order to study the effect of an external pressure on the limitation of swelling due to fission-gas precipitation, some irradiations have been carried out at burn-ups of about 35.000 MWd/ton, and at average sample temperatures of 575 Celsius degrees, of non-alloyed uranium and uranium 8 per cent molybdenum gained in a thick stainless steel can. A cylindrical central hole allows a fuel swelling from 20 to 33 per cent according to the experiment. After irradiation, the uranium samples showed two types of can rupture: one is due to the fuel swelling, and the other, to the pressure of the fission gases, released through a network of microcracks. The cans of the uranium-molybdenum samples are all undamaged and it is shown that the gas release occurs by interconnection of the bubbles for swelling values higher than those obtained in the case of uranium. For each type of fuel, a swelling-fission gas release relationship is established. The results suggest that good performances with a metallic fuel intended for use in fast reactor conditions can be obtained. (author) [French] Afin d'etudier l'effet d'une pression exterieure sur la limitation du gonflement due a la precipitation des gaz de fission, on a irradie a des taux de combustion d'environ 35.000 MWj/t et a des temperatures moyennes de 575 degres des echantillons d'uranium non allie et d'uranium-molybdene 8 pour cent contenus dans une gaine en acier inoxydable epaisse. Un trou cylindrique central permet au combustible de gonfler librement de 20 a 33 pour cent suivant les cas. Apres irradiation les echantillons d'uranium presentent deux types de ruptures de gaine: l'une due au gonflement du combustible, l'autre a la pression des gaz degages, ce degagement des gaz etant provoque par un reseau de micro-fissures. Les gaines des echantillons d'alliage uranium-molybdene sont toutes intactes et l'on montre que le relachement des gaz opere par interconnexion des bulles pour des valeurs de gonflement plus elevees que dans

Technical Cooperation Report for 2007. Report by the Director General; Rapport sur la Cooperation Technique pour 2007. Rapport du Directeur General

Energy Technology Data Exchange (ETDEWEB)

NONE

2008-08-15

, a ete adopte en Afrique. Dans la Division pour l'Asie et le Pacifique, la strategie a moyen terme du RCA et son plan de mise en oeuvre pour 2006-2011, publies en 2006, ont continue a montrer leur utilite. La partie B du present document fait suite aux paragraphes de la resolution GC(51)/RES/13 relatifs a l'assistance a fournir aux Etats membres en ce qui concerne le caractere pacifique, la surete, la securite et la reglementation des applications de l'energie atomique et des techniques nucleaires dans des domaines particuliers. Elle met en avant les activites et realisations de la cooperation technique dans chaque region en 2007, en decrivant les priorites regionales et les mesures prises pour repondre aux priorites nationales. Les objectifs du millenaire pour le developpement etant toujours au centre des preoccupations, le rapport montre comment l'AIEA contribue aux efforts mondiaux de lutte contre la pauvrete, la faim et les maladies et promeut la protection durable de l'environnement et la sante des meres et des enfants. En 2007, les questions de sante en Asie ont notamment fait l'objet de projets regionaux de formation de nouveaux membres du personnel medical, et en Europe, des services de radiotherapie des Balkans ont ete modernises. En Afrique, des projets pour l'amelioration de la sante animale et de la productivite agricole ont contribue a la lutte contre la faim, et en Amerique latine, des activites d'enrichissement des aliments et de determination des carences en vitamines ont permis d'ameliorer la sante des meres et des enfants. (author)

Fuel and combustion stratification study of Partially Premixed Combustion

NARCIS (Netherlands)

Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

2016-01-01

Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

Maximal combustion temperature estimation

International Nuclear Information System (INIS)

Golodova, E; Shchepakina, E

2006-01-01

This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

Effect of Variant End of Injection Period on Combustion Process of Biodiesel Combustion

Directory of Open Access Journals (Sweden)

Khalid Amir

2016-01-01

Full Text Available Biodiesel is an alternative fuel as a replacement to the standard diesel fuel in combustion diesel engine. The biodiesel fuel has a significantly influences throughout the combustion process and exhaust emission. The purpose of this research is to investigate the combustion process behavior during the End of Injection (EOI period and operates under variant conditions using Rapid Compression Machine (RCM. Experimental of RCM is used to simulate a combustion process and combustion characteristics of diesel engine combustion. Three types of biodiesel blend which are B5, B10 and B15 were tested at several injection pressures of 80 MPa, 90 MPa and 130 MPa under different ambient temperatures, 750 K to 1100 K. The results of this study showed that the ignition delay slightly reduced with increasing the content of biodiesel blends from B5, B10 and B15 and became more shorten as the injection pressure been enhanced. As the injection pressure increased, the behavior of combustion pressure at end of injection is reduced, radically increased the NOX emission. It is noted that the process of combustion at the end of injection increased as the ambient temperature is rising. In fact, higher initial ambient temperature improved the fuel atomization and mixing process. Under the biodiesel combustion with higher ambient temperature condition, the exhaust emission of CO, O2, and HC became less but increased in NOX emission. Besides, increased in blends of biodiesel ratio are found to enhance the combustion process, resulted a decreased in HC emissions.

Jet plume injection and combustion system for internal combustion engines

Science.gov (United States)

Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

1993-01-01

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

Path planning during combustion mode switch

Science.gov (United States)

Jiang, Li; Ravi, Nikhil

2015-12-29

Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

Combustion, detonation, shock waves. Proceedings of the Zel'dovich memorial - International conference on combustion. Volume 1

International Nuclear Information System (INIS)

Merzhanov, A.G.; Frolov, S.M.

1995-01-01

This book contains lectures by the experts in various fields of modern research in combustion, detonation and shock waves, presented at the Zel'dovich memorial - International conference on combustion dedicated to the 80-th birthday of academician Ya.B. Zel'dovich. There are eight chapters discussing the state-of-the-art in combustion kinetics, ignition and steady-state flame propagation, diffusion and heterogeneous combustion, turbulent combustion, unsteady combustion, detonation, combustion and detonation analogies, intense shock waves and extreme states of matter [ru

Fuels and Combustion

KAUST Repository

Johansson, Bengt

2016-08-17

This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

Fuels and Combustion

KAUST Repository

Johansson, Bengt

2016-01-01

This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

Burnup determination of power reactor fuel elements by gamma spectrometry; Determination par spectrometrie {gamma} du taux d'irradiation des elements combustibles des reacteurs de puissance

Energy Technology Data Exchange (ETDEWEB)

Robin, M; Jastrzeb, M; Boisliveau, S; Boyer, R; Vidal, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

This report describes a method for determining by {gamma} spectrometry the burn up and the specific power of fuel elements irradiated in power reactors. The energy spectrum of {gamma} rays emitted by fission products is measured by means of a simple equipment using a sodium iodide detector and a multichannel analyzer. In order to extract from the spectrum a quantity proportional to the burn up, it is necessary to: - isolate an activity specific of one emitter,- give the same importance to fissions in uranium and plutonium - take into account the radioactive decay during and after irradiation. One hundred fuel elements were studied and burn up values obtained by {gamma} spectrometry are compared to results given by chemical analyses. Preliminary measurements show that the accuracy of the results is greatly increased by the use of a germanium detector, due to its good resolution. (authors) [French] Ce rapport expose une methode de determination par spectrometrie {gamma} du taux d'irradiation et de la puissance specifique des elements combustibles irradies dans les reacteurs de puissance. Une installation simple utilisant un detecteur d'iodure de sodium et un selecteur multicanaux mesure le spectre en energie du rayonnement {gamma} emis par les produits de fission. Afin d'extraire du spectre une quantite proportionnelle au taux de combustion, il faut: - isoler une activite specifique a un emetteur, - donner la meme importance aux fissions survenues dans l'uranium et le plutonium, - prendre en compte la decroissance radioactive pendant et apres l'irradiation. Les mesures ont porte sur une centaine d'elements combustibles et les taux de combustion obtenus par spectrometrie {gamma} sont compares aux resultats des analyses chimiques. Des mesures preliminaires montrent que l'utilisation d'un detecteur de germanium augmente considerablement la precision des resultats, en raison de son excellente resolution. (auteurs)

Study of some continuous spectra produced by nuclear reactions with light nuclei; Etude de quelques spectres continus produits par reactions nucleaires avec des noyaux legers

Energy Technology Data Exchange (ETDEWEB)

Marquez, L

1966-07-01

The continuous spectra coming from several nuclear reactions with light nuclei were measured. The spectra can be explained by a two-step reaction mechanism; however, the reactions produced by {sup 6}Li are different. A mechanism was proposed to explain their spectra based on the following assumptions: {sup 6}Li makes a nuclear molecule with the target which subsequently breaks up in such a way that an {alpha} particle comes out with the kinetic energy that it has in the molecule. The calculated spectra and those measured are in good agreement. (author) [French] Nous avons mesure les spectres continus produits dans plusieurs reactions nucleaires avec des noyaux legers. A l'exception des spectres produits par {sup 6}Li, on a trouve qu'on pouvait expliquer ces spectres par le mecanisme des reactions en deux etapes. Nous avons propose un mecanisme pour expliquer les spectres produits par {sup 6}Li. On suppose que {sup 6}Li forme une molecule nucleaire avec la cible qui eclate ensuite de facon telle qu'une particule alpha de la molecule sort avec l'energie cinetique de son mouvement propre dans la molecule. Les spectres calcules avec ces hypotheses et les spectres mesures sont en bon accord. (auteur)

Molten salts in nuclear reactors; Les sels fondus dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Dirian, J; Saint-James, [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

Collection of references dealing with the physicochemical studies of fused salts, in particular the alkali and alkali earth halides. Numerous binary, ternary and quaternary systems of these halides with those of uranium and thorium are examined, and the physical properties, density, viscosity, vapour pressure etc... going from the halides to the mixtures are also considered. References relating to the corrosion of materials by these salts are included and the treatment of the salts with a view to recuperation after irradiation in a nuclear reactor is discussed. (author) [French] Bibliographie regroupant l'etude physico-chimique des sels fondus, en particulier des halogenures alcalins et alcalino-terreux. On etudie de nombreux systemes binaires, ternaires et quaternaires de ces halogenures avec des halogenures d'uranium, et de thorium. On etudie egalement les proprietes physiques des halogenures ou des melanges d'halogenures (densite, viscosite, tension de vapeur, etc...). On donne egalement des references quant a la corrosion des materiaux par ces sels, et le traitement de ceux-ci en vue de recuperation, apres irradiation dans un reacteur nucleaire. (auteur)

Production of nuclear graphite in France; Production de graphite nucleaire en France

Energy Technology Data Exchange (ETDEWEB)

Legendre, P; Mondet, L [Societe Pechiney, 74 - Chedde (France); Arragon, Ph; Cornuault, P; Gueron, J; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1955-07-01

The graphite intended for the construction of the reactors is obtained by the usual process: confection of a cake from coke of oil and tar, cooked (in a electric oven) then the product of cook is graphitized, also by electric heating. The use of the air transportation and the control of conditions cooking and graphitization have permitted to increase the nuclear graphite production as well as to better control their physical and mechanical properties and to reduce to the minimum the unwanted stains. (M.B.) [French] Le graphite destine a la construction des reacteurs est obtenu par le procede usuel: confection d'une pate a partir de coke de petrole et de brai, cuisson de cette pate (au four electrique) puis graphitation du produit cuit, egalement par chauffage electrique. L'usage du transport pneumatique et le controle des conditions cuisson et de graphitation ont permit d'augmenter la production de graphite nucleaire ainsi que de mieux controler ses proprietes physiques et mecaniques et de reduire au minimum les souillures accidentelles. (M.B.)

Mesures de procédure spéciales et respect des droits de l'homme Rapport général

OpenAIRE

Vervaele, J.A.E.

2009-01-01

Le but du rapport général est de mener une analyse comparative des rapports nationaux en vue de présenter les processus de transformation des systèmes de justice pénale internes, en particulier du procès pénal, étant donné que des mesures procédurales spéciales sont introduites pour appréhender le terrorisme et la criminalité organisée, et de voir si cela a conduit les pays à se départir de leur propres règles fondamentales, procédures, principes et standards des droits de l’homme applicables...

General trends in the use of uranium in the nuclear industry; Tendances generales d'emploi de l'uranium dans les industries nucleaires

Energy Technology Data Exchange (ETDEWEB)

Salesse, M [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

It can be seen from a consideration of the development of the military and civil needs for uranium that, in the long run, the main outlet for the metal will be provided by its industrial applications. The technical uncertainties concerning the best method of producing atomic energy are still numerous and in fact reflect the hesitation in choosing one of two classes of fuel: that based on the metal and that based on the oxide. Four main factors should influence the choice: - the neutron reactivity and the enrichment of the uranium; - the operating temperature; - the resistance to radiation effects; - the chemical stability; but in actual fact, when the choice for a particular use has to be made, it will be another type of factor, such as the cost price, and weight and space considerations which will determine the choice of either metallic uranium or uranium oxide reactors. (author) [French] D'apres le developpement des besoins militaires ou civils en uranium, on voit que les usages industriels de ce metal constituent, a long terme, le debouche essentiel. Les incertitudes techniques, sur le procede optimum pour faire de l'energie nucleaire, restent nombreuses, et se traduisent finalement par une hesitation entre deux grandes classes de combustibles: ceux a base de metal et ceux a base d'oxyde: la preference a l'une ou l'autre de ces deux categories doit s'inspirer de quatre considerations: - la reactivite neutronique et l'enrichissement de l'uranium; - la temperature de fonctionnement; - la resistance aux effets du rayonnement; - la stabilite chimique; mais en definitive, lorsqu'il s'agira d'une application determinee, ce seront des considerations d'un autre ordre, comme le prix de revient, le poids et l'encombrement, qui determineront le choix entre piles a uranium metallique et piles a oxyde d'uranium. (auteur)

Lump wood combustion process

Science.gov (United States)

Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

2014-08-01

The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

Combustion Research Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

Le rapport Coopération pour le développement de l'OCDE souligne ...

International Development Research Centre (IDRC) Digital Library (Canada)

14 févr. 2018 ... Cette 55e édition du rapport Coopération pour le développement fournit une analyse exhaustive des contraintes liées aux données auxquelles les pays en développement sont confrontés de nos jours, ainsi que des options stratégiques visant à compiler de meilleures statistiques pour le développement ...

Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

Energy Technology Data Exchange (ETDEWEB)

Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

2005-03-01

This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

Twenty-fifth symposium (international) on combustion

International Nuclear Information System (INIS)

Anon.

1994-01-01

Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

International Nuclear Information System (INIS)

Warzecha, Piotr; Boguslawski, Andrzej

2014-01-01

Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

J'ai le plaisir de vous présenter le quatrième rapport annuel du ...

International Development Research Centre (IDRC) Digital Library (Canada)

ACCA

savoir autochtone en matière de prévisions météorologiques. ... Le rapport comporte en outre une carte des liens tissés par nos partenaires de recherche avec les décideurs aux échelles locale, nationale et régionale dans le cadre des efforts.

The pulsed neutron method applied to the determination of the nuclear constants of graphite (1961); La methode des neutrons pulses appliquee a la determination des constantes nucleaires du graphite (1961)

Energy Technology Data Exchange (ETDEWEB)

Lalande, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1961-07-01

A method for determining the nuclear constants {sigma}{sub a} and {lambda}{sub t} of a moderator is described. The disappearance of a burst of neutrons introduced into a finite medium is studied as a function of time. This decrease in the thermal neutron density is the product of two exponentials; one representing the absorption, the other the leakage. By varying one or other of these factors, the constants of the factor left unvaried can be determined, and from this the nuclear constant values are deduced. (author) [French] On decrit une methode permettant de determiner les constantes nucleaires {sigma}{sub a} et {lambda}{sub t} d'un moderateur. On etudie la decroissance dans le temps d'une bouffee de neutrons introduite dans un milieu fini. Cette decroissance de la densite en neutrons thermiques est le produit de deux exponentielles; l'une represente l'absorption, l'autre les fuites. Par variation de l'un ou l'autre de ces facteurs, on determine les constantes du facteur laisse invariant dont on deduit les valeurs des constantes nucleaires. (auteur)

High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

NARCIS (Netherlands)

Sliphorst, M.

2011-01-01

Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

Decrease of noxious emissions in the residual fuel oil combustion; Disminucion de emisiones nocivas en la combustion de aceite combustible residual

Energy Technology Data Exchange (ETDEWEB)

Mandoki W, Jorge [Econergia S. de R. L. de C. V. Mexico, D. F. (Mexico)

1994-12-31

The residual fuel oil combustion emits noxious substances such as carbonaceous particulate, nitrogen oxides, and sulfur trioxide at unacceptable levels. Water emulsified in the fuel substantially reduces such emissions, achieving besides, in most of the cases, a net saving in the fuel consumption. The beneficial effects are shown in burning the residual fuel oil as a water emulsion, as well as the method to produce an adequate emulsion. The emulsified fuel technology offers a low cost option to reduce air pollution. The fuel oil quality has been declining during the last decades due to: 1. Increase in the production of crude heavy oils, generally with higher content of asphaltens and sulfur. 2. Less availability of vacuum distillation residues due to its conversion into greater value products. 3. More intensive conversion processes such as catalytic cracking, visbreaking, etc. that increase the asphaltenes concentration in the bottoms, causing instability problems. 4. The increase in the vanadium and other metals content as the concentration of asphaltenes increases. The use of emulsified fuel oil provides an efficient and economical method to substantially reduce the noxious emissions to the atmosphere. The emulsion contains water particles in a diameter between 2 and 20 microns, uniformly distributed in the fuel oil, generally in a proportion generally of 5 to 10%; besides, it contains a tensioactive agent to assure a stable emulsion capable of withstanding the shearing forces of the pumping and distribution systems. When the atomized oil drops get into the combustion chamber, the emulsified water flashes into high pressure steam, originating a violent secondary atomization. The effect of this secondary atomization is the rupture of the oil drops of various hundred microns, producing drops of 5 to 15 microns in diameter. Since the necessary time for combustion is an exponential function of the drop diameter, a very substantial improvement in the combustion is

Combustion Research Facility

Data.gov (United States)

Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

Science.gov (United States)

Roberts, Jr., Charles E.; Chadwell, Christopher J.

2004-09-21

The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

Fuel Combustion Laboratory | Transportation Research | NREL

Science.gov (United States)

Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

Sandia Combustion Research: Technical review

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-07-01

This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

Aspects chimiques de la combustion du charbon pulvérisé. Première partie Chemical Aspects of the Combustion of Pulverized Coal. Part One

Directory of Open Access Journals (Sweden)

De Soete G. G.

2006-11-01

Full Text Available II n'est pas facile de parvenir à une vue complète des multiples phénomènes chimiques dont la flamme de charbon pulvérisé est le siège. La présente étude bibliographique s'efforce de donner plus qu'une juxtaposition des données de la littérature récente, en risquant une tentative de présentation cohérente des mécanismes chimiques clés qui s'affrontent dans cette combustion. Ces mécanismes font intervenir des réactions en phase gazeuse relativement rapides (combustion des produits gazeux de pyrolyse, formation d'oxydes d'azote à partir de l'azote organique ainsi qu'un certain nombre de réactions hétérogènes très importantes (dévolatilisation pyrolysante rapide, oxydation du coke, réduction hétérogène d'oxydes d'azote qui peuvent se dérouler de façon beaucoup plus lente. En ce qui concerne ces dernières, le régime non isotherme, auquel les soumet l'existence de gradients de température dans la flamme industrielle, entraîne souvent des conséquences non négligeables pour le déroulement de ces mécanismes cinétiques complexes : ainsi la quantité et la composition des produits de pyrolyse est fortement tributaire de ces conditions non isothermes. Carrefour de plusieurs mécanismes chimiques complexes, la flamme de charbon est caractérisée chimiquement par un grand nombre de cas de compétition : a compétition entre différentes voies réactionnelles à l'intérieur d'un mécanisme donné ; à titre d'exemple typique : la pyrolyse du charbon ; b compétition entre phénomènes chimiques et physiques, également à l'intérieur d'un même mécanisme, entraînant la transition éventuellement réversible d'un régime cinétique vers un régime diffusionnel, comme c'est le cas dans l'oxydation du coke, avec des conséquences sensibles pour la vitesse réactionnelle globale et sa dépendance par rapport à la température, pouvant même aller jusqu'à l'extinction de la combustion du coke ; c compétition entre

COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

Directory of Open Access Journals (Sweden)

Nureddin Dinler

2010-01-01

Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

International Nuclear Information System (INIS)

Prayitno; Sukosrono

2007-01-01

The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

Mesures de procédure spéciales et respect des droits de l'homme
Rapport général

OpenAIRE

John A.E. Vervaele

2009-01-01

Le but du rapport général est de mener une analyse comparative des rapports nationaux en vue de présenter les processus de transformation des systèmes de justice pénale internes, en particulier du procès pénal, étant donné que des mesures procédurales spéciales sont introduites pour appréhender le terrorisme et la criminalité organisée, et de voir si cela a conduit les pays à se départir de leur propres règles fondamentales, procédures, principes et standards des droits de l’homme applicables...

Biofuels combustion.

Science.gov (United States)

Westbrook, Charles K

2013-01-01

This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

Low emission internal combustion engine

Science.gov (United States)

Karaba, Albert M.

1979-01-01

A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

Alcohol combustion chemistry

KAUST Repository

Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

2014-01-01

. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

Diesel oil combustion in fluidized bed; Combustion de aceite diesel en lecho fluidizado

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Cazares, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-07-01

The effect of the fluidized bed depth in the combustion in burning diesel oil in a fluidized bed, was analyzed. A self sustained combustion was achieved injecting the oil with an injector that utilized a principle similar to an automobile carburetor venturi. Three different depths were studied and it was found that the deeper the bed, the greater the combustion efficiency. Combustion efficiencies were attained from 82% for a 100mm bed depth, up to 96% for a 200mm bed depth. The diminution in the efficiency was mainly attributed to unburned hydrocarbons and to the carbon carried over, which was observed in the black smoke at the stack outlet. Other phenomena registered were the temperature gradient between the lower part of the bed and the upper part, caused by the fluidization velocity; additionally it was observed that the air employed for the oil injection (carbureting air) is the most important parameter to attain a complete combustion. [Espanol] Se analizo el efecto de la profundidad del lecho en la combustion al quemar aceite diesel en un lecho fluidizado experimental. Se logro combustion autosostenida inyectando el aceite con un inyector que utilizo un principio similar al venturi del carburador de automovil. Se estudiaron tres diferentes profundidades del lecho y se encontro que a mayor profundidad del lecho, mayor eficiencia de la combustion. Se lograron eficiencias de la combustion desde 82% para el lecho de 100 mm de profundidad hasta 96% para el de 200 mm. La disminucion de la eficiencia se atribuyo, principalmente, a los hidrocarburos no quemados y al carbon arrastrado, lo cual se observo en el humo negro a la salida de la chimenea. Otros fenomenos registrados fueron el gradiente de temperatura entre la parte baja del lecho y la parte superior causado por la velocidad de fluidizacion; ademas, se observo que el aire utilizado para inyectar el aceite (aire de carburacion) es el parametro mas importante para lograr una combustion completa.

Transient flow combustion

Science.gov (United States)

Tacina, R. R.

1984-01-01

Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

Study and installation of concrete shielding in the civil engineering of nuclear construction (1960); Etude et mise en place des betons de protection dans le genie civil des ouvrages nucleaires (1960)

Energy Technology Data Exchange (ETDEWEB)

Dubois, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The object of this report is to give technical information about high density concretes which have become very important for radiation biological shielding. The most generally used heavy aggregates (barytes, ilmenite, ferrophosphorus, limonite, magnetite and iron punching) to make these concretes are investigated from the point of view prospecting and physical and chemical characteristics. At first, a general survey of shielding concretes is made involving the study of components, mixing and placing methods, then, a detailed investigation of some high density concretes: barytes concrete, with incorporation of iron punching or iron shot, ferrophosphorus concrete, ilmenite concrete and magnetite concrete, more particularly with regard to grading and mix proportions and testing process. To put this survey in concrete form, two practical designs are described such as they have been carried out at the Saclay Nuclear Station. Specifications are given for diverse concretes and for making the proton-synchrotron 'Saturne' shielding blocks. (author) [French] Ce rapport a pour objet de donner des precisions techniques au sujet des betons a haute densite qui ont pris une grande importance pour la protection biologique contre les rayonnements. Les agregats lourds les plus couramment utilises (barytine, ilmenite, ferrophosphore, limonite, magnetite et riblons) pour la fabrication de ces betons, sont examines du point de vue prospection et caracteristiques physiques et chimiques. On procede d'abord a une etude generale des betons de protection comprenant l'etude des constituants, de la confection et de la mise en place, ensuite, a un examen detaille de quelques betons a haute densite: betons a base de barytine, avec incorporation de riblons ou de grenaille de fonte, betons au ferrophosphore, a base d'ilmenite ou de magnetite, notamment en ce qui concerne la granulometrie, la composition, le dosage et les processus d'essais. Pour concretiser ces etudes, deux applications pratiques

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux

Study of thick, nuclear-compensated silicon detectors; Etude des detecteurs epais au silicium compense nucleairement

Energy Technology Data Exchange (ETDEWEB)

Le Coroller, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-09-01

A study is made here, from the point of view of the realization and the performance, of thick nuclear-compensated silicon detectors. After recalling the need for compensation and reviewing the existing methods, the author describes in detail the controlled realization of thick detectors by nuclear compensation from the theoretical and experimental points of view. The practical precautions which should be observed are given: control of the homogeneity of the starting material, control of the evolution of the compensation, elimination of parasitic processes. The performances of the detectors obtained are then studied: electrical characteristics (current, life-time) on the one hand, detection and spectrometry of penetrating radiations on the other hand. The results show, that the compensated diodes having an effective thickness of two millimeters operate satisfactorily as detectors for applied voltages of about 500 volts. The resolutions observed are then about 2 per cent for mono-energetic electrons and about 4 per cent for the gamma; they can be improved by the use of a pre-amplifier of very low background noise. (author) [French] Les detecteurs epais au silicium compense nucleairement sont etudies ici du double point de vue realisation et performances. Apres un rappel sur la necessite de la compensation et les procedes existants, la realisation controlee des detecteurs epais par compensation nucleaire est decrite en detail sous l'aspect theorique et l'aspect experimental. On met en evidence les precautions a prendre dans la pratique: controle de l'homogeneite du materiau de base, controle de l'evolution de la compensation, elimination des processus parasites. On etudie ensuite les performances de detecteurs obtenus : caracteristiques electriques (courant, duree de vie) d'une part, d'autre part detection et spectrometrie des rayonnements penetrants. Les resultats montrent que les diodes compensees ayant une epaisseur utile de deux millimetres fonctionnent

Shale oil combustion

International Nuclear Information System (INIS)

Al-dabbas, M.A.

1992-05-01

A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

Shale oil combustion

Energy Technology Data Exchange (ETDEWEB)

Al-dabbas, M A

1992-05-01

A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion.

Science.gov (United States)

Chien, Y C; Yang, S H

2013-01-01

Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.

Corrosion by cooling gases in nuclear reactors; la corrosion par les gaz caloporteurs dans les reacteurs nucleaires

Energy Technology Data Exchange (ETDEWEB)

Darras, R. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de Saclay, Section d' etude de la corrosion par gaz et metaux liquides (France)

1960-07-01

This article begins with a review of the various materials which can be used and the cooling gases in which they may be heated, emphasis being placed on the importance of reaching temperatures as high as possible. This is followed by a few general remarks on the dry oxidation of metals and alloys, particularly with regard to diffusion phenomena and their various possible mechanisms, and also the methods of investigation employed. Finally, the behaviour of the chief nuclear materials heated in the various gases is studied successively. Materials used for fuel (metallic uranium, uranium oxide, carbides and silicides), canning materials (magnesium, aluminium, zirconium, beryllium, stainless and refractory steels), structural materials (ordinary or slightly alloyed steels), and finally moderators (graphite, beryllium oxide) are deal with in this way. This account is backed up both by the results obtained at the CEA and by work published outside or abroad up to the present day. In conclusion, every effort has been made to direct future research on the basis of the foregoing. Reprint of a paper published in Industries Atomiques - no. 9/10, 1959, p. 3-23 [French] Dans cet article, on passe tout d'abord en revue les divers materiaux utilisables et les gaz de refroidissement dans lesquels ils peuvent etre chauffes, en insistant sur l'interet d'atteindre des temperatures aussi elevees que possible. On rappelle ensuite quelques generalites sur l'oxydation seche des metaux et alliages, notamment en ce qui concerne les phenomenes de diffusion et leurs divers mecanismes possibles ainsi que les methodes d'etude. Enfin, le comportement des principaux materiaux nucleaires chauffes dans les divers gaz est etudie successivement. On traita ainsi des materiaux combustibles (uranium metallique, oxyde, carbures et siliciures d'uranium), des materiaux de gainage (magnesium, aluminium, zirconium, beryllium, aciers inoxydables et refractaires), des materiaux de structure (aciers ordinaires

The Multi-User Droplet Combustion Apparatus: the Development and Integration Concept for Droplet Combustion Payloads in the Fluids and Combustion Facility Combustion Integrated Rack

Science.gov (United States)

Myhre, C. A.

2002-01-01

The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility designed to accommodate four different droplet combustion science experiments. The MDCA will conduct experiments using the Combustion Integrated Rack (CIR) of the NASA Glenn Research Center's Fluids and Combustion Facility (FCF). The payload is planned for the International Space Station. The MDCA, in conjunction with the CIR, will allow for cost effective extended access to the microgravity environment, not possible on previous space flights. It is currently in the Engineering Model build phase with a planned flight launch with CIR in 2004. This paper provides an overview of the capabilities and development status of the MDCA. The MDCA contains the hardware and software required to conduct unique droplet combustion experiments in space. It consists of a Chamber Insert Assembly, an Avionics Package, and a multiple array of diagnostics. Its modular approach permits on-orbit changes for accommodating different fuels, fuel flow rates, soot sampling mechanisms, and varying droplet support and translation mechanisms to accommodate multiple investigations. Unique diagnostic measurement capabilities for each investigation are also provided. Additional hardware provided by the CIR facility includes the structural support, a combustion chamber, utilities for the avionics and diagnostic packages, and the fuel mixing capability for PI specific combustion chamber environments. Common diagnostics provided by the CIR will also be utilized by the MDCA. Single combustible fuel droplets of varying sizes, freely deployed or supported by a tether are planned for study using the MDCA. Such research supports how liquid-fuel-droplets ignite, spread, and extinguish under quiescent microgravity conditions. This understanding will help us develop more efficient energy production and propulsion systems on Earth and in space, deal better with combustion generated pollution, and address fire hazards associated with

Large-eddy simulation of ethanol spray combustion using a finite-rate combustion model

Energy Technology Data Exchange (ETDEWEB)

Li, K.; Zhou, L.X. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics; Chan, C.K. [Hong Kong Polytechnic Univ. (China). Dept. of Applied Mathematics

2013-07-01

Large-eddy simulation of spray combustion is under its rapid development, but the combustion models are less validated by detailed experimental data. In this paper, large-eddy simulation of ethanol-air spray combustion was made using an Eulerian-Lagrangian approach, a subgrid-scale kinetic energy stress model, and a finite-rate combustion model. The simulation results are validated in detail by experiments. The LES obtained statistically averaged temperature is in agreement with the experimental results in most regions. The instantaneous LES results show the coherent structures of the shear region near the high-temperature flame zone and the fuel vapor concentration map, indicating the droplets are concentrated in this shear region. The droplet sizes are found to be in the range of 20-100{mu}m. The instantaneous temperature map shows the close interaction between the coherent structures and the combustion reaction.

Impacts of Combustion Conditions and Photochemical Processing on the Light Absorption of Biomass Combustion Aerosol.

Science.gov (United States)

Martinsson, J; Eriksson, A C; Nielsen, I Elbæk; Malmborg, V Berg; Ahlberg, E; Andersen, C; Lindgren, R; Nyström, R; Nordin, E Z; Brune, W H; Svenningsson, B; Swietlicki, E; Boman, C; Pagels, J H

2015-12-15

The aim was to identify relationships between combustion conditions, particle characteristics, and optical properties of fresh and photochemically processed emissions from biomass combustion. The combustion conditions included nominal and high burn rate operation and individual combustion phases from a conventional wood stove. Low temperature pyrolysis upon fuel addition resulted in "tar-ball" type particles dominated by organic aerosol with an absorption Ångström exponent (AAE) of 2.5-2.7 and estimated Brown Carbon contributions of 50-70% to absorption at the climate relevant aethalometer-wavelength (520 nm). High temperature combustion during the intermediate (flaming) phase was dominated by soot agglomerates with AAE 1.0-1.2 and 85-100% of absorption at 520 nm attributed to Black Carbon. Intense photochemical processing of high burn rate flaming combustion emissions in an oxidation flow reactor led to strong formation of Secondary Organic Aerosol, with no or weak absorption. PM1 mass emission factors (mg/kg) of fresh emissions were about an order of magnitude higher for low temperature pyrolysis compared to high temperature combustion. However, emission factors describing the absorption cross section emitted per kg of fuel consumed (m(2)/kg) were of similar magnitude at 520 nm for the diverse combustion conditions investigated in this study. These results provide a link between biomass combustion conditions, emitted particle types, and their optical properties in fresh and processed plumes which can be of value for source apportionment and balanced mitigation of biomass combustion emissions from a climate and health perspective.

Engine combustion network (Ecn) : characterization and comparison of boundary conditions for different combustion vessels

NARCIS (Netherlands)

Meijer, M.; Somers, L.M.T.; Johnson, J.; Naber, J.; Lee, S.Y.; Malbec, L.M.; Bruneaux, G.; Pickett, L.M.; Bardi, M.; Payri, R.; Bazyn, T.

2012-01-01

The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels and/or performing computational fluid dynamics (CFD) simulation, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray

Optimization of combustion chamber geometry for stoichiometric diesel combustion using a micro genetic algorithm

Energy Technology Data Exchange (ETDEWEB)

Park, Sung Wook

2010-11-15

This paper describes the optimization of combustion chamber geometry and engine operating conditions for stoichiometric diesel combustion, targeting lower gross indicated specific fuel consumption. The KIVA code, coupled with a micro genetic algorithm population of nine for each generation was used. The optimization variables were composed of ten variables related to the combustion chamber geometry and engine operating conditions. In addition, an auto mesh generator was developed for generating various kinds of combustion chambers, such as open-crater, re-entrant, deep, and shallow types. In addition, the computational models were validated against the experimental results for a stoichiometric process in terms of the combustion pressure history and emissions. Through the preset optimization, a 35% improvement in the gross indicated that specific fuel consumption was achieved. In addition, the optimization results showed that the optimum engine operating conditions employed a premixed charge compression ignition combustion regime with early injection and a narrow spray included angle. Furthermore, a higher boost pressure was used to prevent fuel film formation. (author)

Measurements for uranium-light water subcritical assembly; Mesures pour ensemble sous-critique uranium-eau legere d'enseignement

Energy Technology Data Exchange (ETDEWEB)

Barre, J Y [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1964-07-01

The aim of this report is to determine the matter Laplacian of a subcritical assembly, done for educational purposes, using natural uranium combustible and light water for the moderator and the reflector. (M.B.) [French] L'objet de ce rapport est la determination du Laplacien matiere d'un reseau sous-critique, destine a l'enseignement, utilisant comme combustible l'uranium naturel et comme moderateur et reflecteur l'eau naturelle. (M.B.)

Multi-stage combustion using nitrogen-enriched air

Science.gov (United States)

Fischer, Larry E.; Anderson, Brian L.

2004-09-14

Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

DIAGNOSIS OF FAILURE OF COMBUSTION IN THE COMBUSTION CHAMBER WITH A THERMOVISION EQUIPMENT

Directory of Open Access Journals (Sweden)

S. V. Vorobiev

2014-01-01

Full Text Available The use of thermovision technology to diagnose failure of the combustion flame test tube of the main combustion chamber gas turbine engine is deal with in the article. Join the thermal radiation of the jet of combustion products and the internal elements was carried out using short-wave thermovision system AGA-782 with spectral spectral filters in several ranges from 3.2 to 5.6 microns. Thermovision is mounted on the axis of the flame tube. The output signal was recorded and processed on a computer in real time, allowing monitor the combustion process and the thermal state of the object during the experiment.

High Combustion Research Facility

Data.gov (United States)

Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

Computational Modeling of Turbulent Spray Combustion

NARCIS (Netherlands)

Ma, L.

2016-01-01

The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

Space Station Freedom combustion research

Science.gov (United States)

Faeth, G. M.

1992-01-01

Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame

Underground treatment of combustible minerals

Energy Technology Data Exchange (ETDEWEB)

Sarapuu, E

1954-10-14

A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

KAUST Repository

An, Yanzhao

2017-09-23

In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

KAUST Repository

An, Yanzhao; Jaasim, Mohammed; Vallinayagam, R.; Vedharaj, S.; Im, Hong G.; Johansson, Bengt.

2017-01-01

In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

Fuels and Combustion | Transportation Research | NREL

Science.gov (United States)

Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

Sandia Combustion Research Program

Energy Technology Data Exchange (ETDEWEB)

Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

1988-01-01

During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

Ultra-low pollutant emission combustion method and apparatus

International Nuclear Information System (INIS)

Khinkis, M.J.

1992-01-01

This patent describes a method for ultra-low pollutant emission combustion of fossil fuel. It comprises: introducing into a primary combustion chamber a first fuel portion of about 1 percent to about 20 percent of a total fuel to be combusted; introducing primary combustion air into the primary combustion chamber; introducing a first portion of water into the primary combustion chamber, having a first water heat capacity equivalent to a primary combustion air heat capacity of one of a primary combustion air amount of about 10 percent to about 60 percent of the first stoichiometirc requirement for complete combustion of the first fuel portion and an excess primary combustion air amount of about 20 percent to about 150 percent of the first stoichiometric requirement for complete combustion of the first fuel portion; burning the first fuel portion with the primary combustion air in the primary combustion chamber at a temperature abut 2000 degrees F to about 2700 degrees F producing initial combustion products; passing the initial combustion products into a secondary combustion chamber; introducing into the secondary combustion chamber a second fuel portion of about 80 percent to about 99 percent of the total fuel to be combusted; introducing secondary combustion air into the secondary combustion chamber in an amount of about 105 percent to about 130 percent of a second stoichiometric requirement for complete combustion of the second fuel portion; introducing a second portion of water into the secondary combustion chamber; burning the second fuel portion and any remaining fuel in the initial combustion products; passing the final combustion products into a dilution chamber; introducing dilution air into the dilution chamber; discharging the ultra-low pollutant emission vitiated air form the dilution chamber

Det afghanska valet i svensk media : En diskursanalys av svensk medias rapportering om parlamentsvalet 2010

OpenAIRE

Arvidsson, Jonathan

2013-01-01

Den här uppsatsen analyserar svensk medias rapportering om valet i Afghanistan 2010. Med hjälp av metoder framtagna av Van Dijk har en analys av artiklar som berör valet 2010 gjorts. De teoretiska utgångspunkterna är postkolonialism och orientalism. Med hjälp av de perspektiven och Van Dijks medieanalys analyseras materialet för att tydliggöra strukturer i media.

ANALYSIS OF INTERNAL COMBUSTION ENGINE WITH A NEW CONCEPT OF POROUS MEDIUM COMBUSTION FOR THE FUTURE CLEAN ENGINE

Directory of Open Access Journals (Sweden)

Ashok A Dhale

2010-01-01

Full Text Available At present, the emissions of internal combustion engine can only be improved by catalytic treatments of the exhaust gases. Such treatments, however, result in high costs and relatively low conversion efficiency. This suggests that a new combustion technique should be developed to yield improved primary combustion processes inside the engine with drastically reduced exhaust gas emissions. To fulfill all requirements, Dr. Franz Drust has proposed a new combustion concept to perform homogenous combustion in internal combustion engines. This concept used the porous medium combustion technique and is called "PM-engine". It is shown that the PM combustion technique can be applied to internal combustion engines. Theoretical considerations are presented for internal combustion engines, indicating that an overall improvement in thermal efficiency can be achieved for the PM-engine. This is explained and general performance of the new PM-engines is demonstrated for a single cylinder, water cooled, direct injection diesel engine. Verification of experiments at primary stage is described that were carried out as a part of the present study.

Alcohol combustion chemistry

KAUST Repository

Sarathy, Mani

2014-10-01

Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

Zircaloy-sheathed element rods fitted with thermo-couples; Barre combustible a thermocouple gainee de zircaloy

Energy Technology Data Exchange (ETDEWEB)

Bernardy de Sigoyer, B; Jacques, F; Thome, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-07-01

In order to carry out thermal conductivity measurements on UO{sub 2} in conditions similar to those under which fuel rods are used, it was necessary to measure the temperature at the interior of a fuel element sheathed in zircaloy. The temperatures are taken with Thermocoax type thermocouples, that is to say fitted with a very thin sheath of stainless steel or Inconel. It is known also that fusion welding of zircaloy onto stainless steel is impossible and that high temperature welded joints are very difficult because of their aggressiveness. The technique used consists in brazing the thermocouples to relatively large stainless steel parts and then joining these plugs by electron bombardment welding to diffused stainless steel-zircaloy couplings. The properties of these diffused couplings and of the brazed joints were studied; the various stages in the fabrication of the containers are also described. (authors) [French] Pour des mesures de conductivite thermique de l'UO{sub 2} dans des conditions voisines du fonctionnement des barres combustibles, il s'agissait de mesurer la temperature a l'interieur d'un element combustible gaine de zircaloy. Les prises de temperature sont faites par thermocouples du type Thermocoax, c'est-a-dire pourvu d'une gaine tres mince en inox ou inconel. Par ailleurs on sait que le soudage par fusion du zircaloy sur l'inox est impossible et que les brasures a haute temperature sont difficiles car tres agressives. La technique utilisee consiste a braser les thermocouples sur des pieces en inox relativement massives et de rapporter par soudage au bombardement electronique ces bouchons sur des raccords diffuses zircaloy-inox. Les proprietes de ces raccords diffuses et celles de joints brases ont ete etudiees; on expose egalement les diverses etapes de fabrication des containers. (auteurs)

“Let Me Tell You About My…” Provider Self-Disclosure in the Emergency Department Builds Patient Rapport

Directory of Open Access Journals (Sweden)

Zink, Korie

2017-01-01

Full Text Available As patients become increasingly involved in their medical care, physician-patient communication gains importance. A previous study showed that physician self-disclosure (SD of personal information by primary care providers decreased patient rating of the provider communication skills. The objective of this study was to explore the incidence and impact of emergency department (ED provider self-disclosure on patients’ rating of provider communication skills. A survey was administered to 520 adult patients or parents of pediatric patients in a large tertiary care ED during the summer of 2014. The instrument asked patients whether the provider self-disclosed and subsequently asked patients to rate providers’ communication skills. We compared patients’ ratings of communication measurements between encounters where self-disclosure occurred to those where it did not. Patients reported provider SD in 18.9% of interactions. Provider SD was associated with more positive patient perception of provider communication skills (p<0.05, more positive ratings of provider rapport (p<0.05 and higher satisfaction with provider communication (p<0.05. Patients who noted SD scored their providers’ communication skills as “excellent” (63.4% compared to patients without selfdisclosure (47.1%. Patients reported that they would like to hear about their providers’ experiences with a similar chief complaint (64.4% of patients, their providers’ education (49%, family (33%, personal life (21% or an injury/ailment unlike their own (18%. Patients responded that providers self-disclose to make patients comfortable/at ease and to build rapport. Provider self-disclosure in the ED is common and is associated with higher ratings of provider communication, rapport, and patient satisfaction. [West J Emerg Med. 2017;18(143-49.

Economic Criteria Applied to Nuclear Materials Management; Criteres Economiques Applicables a la Gestion des Matieres Nucleaires; Ehkonomicheskie kriterii, primenyaemye pri kontrole i uchete yadernykh materialov; Criterios Economicos Aplicados a la Administracion de Materiales Nucleares

Energy Technology Data Exchange (ETDEWEB)

Shelley, W. J.; Kuehn, M. N. [Mallinckrodt Chemical Works, St. Charles, MS (United States)

1966-02-15

placed upon such personnel to accept, understand and perform the work. Such personnel selected must be thoroughly and minutely trained in the importance of their activity. Those responsible for the management of nuclear materials must be continually alert to the smallest kind of aberration in the quality and performance of the personnel, the process, the systems, procedures and techniques. Only through such alertness and willingness to revise, so as to secure improvement, does one secure the optimum balance of costs and needs. (author) [French] La gestion des matieres nucleaires doit etre subordonnee aux objectifs principaux du traitement de ces matieres, c'est-a-dire la production d'energie ou la fabrication de produits finis. Les responsables de la gestion des matieres nucleaires doivent donc tenir constamment compte des besoins de la production principale et adapter les methodes de gestion aux operations de facon a pouvoir assurer cette gestion avec un minimum de depenses. Le systeme de gestion des matieres nucleaires doit soigneusement tenir compte des divers facteurs qui influent sur son prix de revient. Il vient en complement des operations et doit entrainer le minimum de frais de personnel et d'analyse et provoquer le moins d'interruptions possible dans les operations. U doit etre integre a ces dernieres, de facon que les renseignements d'ordre quantitatif qu'il permet d'obtenir puissent etre communiques rapidement aux responsables du controle des operations. Le systeme d'enregistrement et de preparation des rapports doit fournir une quantite maximale de donnees subsidiaires. Il doit etre compatible avec les systemes utilises par les fournisseurs et les consommateurs et assurer la diffusion, partout ou cela est possible, de renseignements supplementaires concernant les lots de matieres nucleaires. Les donnees a fournir pour le controle des matieres nucleaires doivent se limiter a celles qui sont necessaires pour s'assurer qu'il n'y a pas de pertes importantes, de

The industrial production of fuel elements; La fabrication en france des elements combustibles

Energy Technology Data Exchange (ETDEWEB)

Boussard, R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Nadal, J [Societe Industrielle de Combustible Nucleaire (SICN), 75 - Paris (France); Pellen, A [Compagnie pour l' Etude et la Realisation de Combustibles Atomiques (CERCA), 75 - Paris (France)

1964-07-01

indiquent pourquoi et comment l'on est passe de la gaine filee a la gaine usinee et mentionnent quelques caracteristiques de l'appareillage utilise ainsi que les controles effectues. Ils donnent egalement quelques indications sur la fabrication et l'usinage des chemises. Apres avoir rappele comment se presente en France a la mi-1964 l'industrie des combustibles nucleaires, les auteurs insistent sur les aspects economiques de la fabrication des elements combustibles. Ils montrent l'importance relative des investissements sur le prix de revient du combustible proprement dit, dont ils examinent ensuite les differentes pertes. Ils font une analyse du prix de revient de l'element combustible complet en tirant les enseignements actuels. Pour conclure les auteurs indiquent les points particuliers sur lesquels doit porter l'action a venir pour diminuer le cout d'une fabrication assez delicate, mais maintenant bien au point, et supputent le developpement de cette branche industrielle nouvelle. 2eme Partie - FABRICATION INDUSTRIELLE DES ELEMENTS COMBUSTIBLES POUR REACTEURS DU TYPE PISCINE: Les auteurs indiquent comment a ete elude en France le probleme de la fabrication industrielle des elements combustibles obtenue par laminage et les trois phases par lesquelles on est passe: 1 - Assemblage des plaques fabriquees aux U.S.A., 2 - Laminage des noyaux fabriques aux U.S.A. pour obtenir les plaques, 3 - Elaboration de l'alliage U.Al et fabrication des noyaux. Ils rappellent ensuite brievement les caracteristiques des differents elements combustibles actuellement fabriques. Ils decrivent ensuite les differents stades de l'elaboration en donnant des indications sur l'appareillage et en insistant sur l'importance des controles effectues a chaque stade. Pour finir ils examinent le developpement futur de ce type de fabrication, compte tenu des ameliorations prevues ou envisageables. (auteurs)

Indoor combustion and asthma.

Science.gov (United States)

Belanger, Kathleen; Triche, Elizabeth W

2008-08-01

Indoor combustion produces both gases (eg, nitrogen dioxide, carbon monoxide) and particulate matter that may affect the development or exacerbation of asthma. Sources in the home include both heating devices (eg, fireplaces, woodstoves, kerosene heaters, flued [ie, vented] or nonflued gas heaters) and gas stoves for cooking. This article highlights the recent literature examining associations between exposure to indoor combustion and asthma development and severity. Since asthma is a chronic condition affecting both children and adults, both age groups are included in this article. Overall, there is some evidence of an association between exposure to indoor combustion and asthma, particularly asthma symptoms in children. Some sources of combustion such as coal stoves have been more consistently associated with these outcomes than other sources such as woodstoves.

Awareness of households to the development of wind energy sites - Reporting on a survey; Receptivite des menages au developpement des sites eoliens. Rapport d'enquete

Energy Technology Data Exchange (ETDEWEB)

Voisard, M.

2000-07-01

This report for the Swiss Federal Office of Energy presents in tables and diagrams the results of a survey involving 421 households in Switzerland, about their awareness to energy issues and, in particular, to all what regards wind energy and wind power plants. Globally, 80% of the persons asked for their opinion believe that electric power demand will continue to increase. 66% of them are in favour of increased use of renewable energy sources and would consequently agree with a 10% more expensive end-user energy price. 89% of the persons taking part to the survey approve the installation of wind energy farms in Switzerland. Moreover, statistics indicates that the households living in regions already equipped with wind farms are significantly more favorable to the creation of new wind energy sites than those not living in these regions. By the end of the day, it turns out that the main reasons for accepting wind energy are environmental concerns as well as the fear of being obliged to use nuclear power. [French] Ce rapport presente par des graphiques et des tableaux le resultat d'un sondage d'opinion aupres de 421 menages en Suisse, sur la sensibilite du public aux problemes de l'energie et plus particulierement sur sa perception de tout ce qui concerne l'energie du vent et son exploitation par l'implantation d'eoliennes. Globalement, 80% des menages pensent que la demande d'energie electrique va poursuivre sa croissance. 66% d'entre eux sont favorables au developpement des energies renouvelables et prets a accepter en consequence une augmentation du prix de l'energie allant jusqu'a 10%. 89% des personnes interrogees sont favorables au developpement des eoliennes en Suisse. De plus, la statistique montre de maniere significative que les menages des regions dans lesquelles sont deja implantes des sites eoliens sont plus favorables au developpement des eoliennes que les autres. Finalement, le respect de l

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission (n.757-1062, december 1957-december 1958) supplement to C.E.A. reports n. 593 and 756; Liste recapitulative des rapports C.E.A. publies par le Commissariat a l'Energie Atomique (du n.757 a 1062, decembre 1957-decembre 1958) complement aux rapports C.E.A. n. 593 et 756

Energy Technology Data Exchange (ETDEWEB)

Schmiterlow, C G; Cohen, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Recapitulative list of the C.E.A. reports published by the French Atomic Energy Commission. (number 757-1062, december 1957 - december 1958). Supplement to C.E.A. reports number 593 and 756. (author) [French] Liste recapitulative des rapports C.E.A. publies par le Commissariat a l'Energie Atomique (du numero 757 au numero 1062, decembre 1957 - decembre 1958). Complement aux rapports C.E.A. numero 593 et 756. (auteur)

Numerical investigation of biogas flameless combustion

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

2014-01-01

Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

Materials for High-Temperature Catalytic Combustion

Energy Technology Data Exchange (ETDEWEB)

Ersson, Anders

2003-04-01

Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

Eating Animals to Build Rapport: Conducting Research as Vegans or Vegetarians

Directory of Open Access Journals (Sweden)

Katie MacDonald

2014-12-01

Full Text Available Notions of hospitality, community, and the fostering of rapport and connection are foundational concerns for conducting research across difference. Drawing on methodological literature, this paper considers how access to various communities and “good” data is structured by the notion that in order to develop rapport researchers accept the “food”, specifically “meat” offered by their hosts. When researchers are vegetarians or vegans, this can entail a conflict in which questions of hospitality, relationships, and responsibility to ethical commitments come to the fore. As such, we analyze methodological literature in which the logic of nonhuman animal sacrifice is considered a means to the ends of research through the development of “rapport”—often coded as an ethical relationship of respect to the participant. We draw on experiences of veg*n researchers to explore how this assumption functions to position the consumption of meat as a necessary undertaking when conducting research, and in turn, denies nonhuman animal subjecthood. We interrogate the assumption that culture and communities are static inasmuch as this literature suggests ways to enter and exit spaces leaving minimal impact, and that posits participants will not trust researchers nor understand their decisions against eating nonhuman animals. We argue that because food consumption is figured as a private and individual choice, animals are not considered subjects in research. Thus, we articulate a means to consider vegan and/or vegetarians politics, not as a marker of difference, but as an attempt to engage in ethical relationships with nonhuman animals. In so doing, we call for the inclusion of nonhuman animals in relationships of hospitality, and thereby attempt to politicize the practice of food consumption while conducting research.

Information report nuclear energy in Europe; Rapport d'information energie nucleaire en Europe

Energy Technology Data Exchange (ETDEWEB)

Montesquiou, A de

2002-07-01

This report takes stock on the nuclear energy situation in Europe. The European Union with more than 40% of the nuclear power capacity in the world, is already confronted with the nuclear energy place and stakes in the future energy policy. The report si presented in two main parts. The first part, ''the assets and the weaknesses of the nuclear energy'', deals with the economical aspects which historically based the choice of the nuclear energy and the induced impacts on the environment. The competitiveness of the nuclear energy but also the wastes management problem are discussed. The second part, ''the diplomatic and juridical framework of the nuclear energy development'', details and presents the limits of the EURATOM treaty. (A.L.B.)

Large eddy simulation and combustion instabilities; Simulation des grandes echelles et instabilites de combustion

Energy Technology Data Exchange (ETDEWEB)

Lartigue, G.

2004-11-15

The new european laws on pollutants emission impose more and more constraints to motorists. This is particularly true for gas turbines manufacturers, that must design motors operating with very fuel-lean mixtures. Doing so, pollutants formation is significantly reduced but the problem of combustion stability arises. Actually, combustion regimes that have a large excess of air are naturally more sensitive to combustion instabilities. Numerical predictions of these instabilities is thus a key issue for many industrial involved in energy production. This thesis work tries to show that recent numerical tools are now able to predict these combustion instabilities. Particularly, the Large Eddy Simulation method, when implemented in a compressible CFD code, is able to take into account the main processes involved in combustion instabilities, such as acoustics and flame/vortex interaction. This work describes a new formulation of a Large Eddy Simulation numerical code that enables to take into account very precisely thermodynamics and chemistry, that are essential in combustion phenomena. A validation of this work will be presented in a complex geometry (the PRECCINSTA burner). Our numerical results will be successfully compared with experimental data gathered at DLR Stuttgart (Germany). Moreover, a detailed analysis of the acoustics in this configuration will be presented, as well as its interaction with the combustion. For this acoustics analysis, another CERFACS code has been extensively used, the Helmholtz solver AVSP. (author)

Rapportering om going concern i den nye revisionspåtegning – særlige forhold for PIE-virksomheder

DEFF Research Database (Denmark)

Seehausen, Jesper

2017-01-01

Artiklen omhandler særlige forhold for PIE-virksomheder, dvs. virksomheder af interesse for offentligheden, vedrørende going concern. Artikel skal læses i sammenhæng med min generelle artikel vedr. rapportering om going concern i den nye revisionspåtegning, idet denne artikel også er relevant...

Manifold methods for methane combustion

Energy Technology Data Exchange (ETDEWEB)

Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

1995-10-01

Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

Science.gov (United States)

Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

2015-01-01

Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

Nuclear developments at the international inter govern mental level (1961); Developpements nucleaires sur le plan international intergouvernemental (1961)

Energy Technology Data Exchange (ETDEWEB)

Waynbaum, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The United Nations organisation and nuclear energy rose simultaneously, in 1945, to occupy an important place in the public eye. The spiritual succession of the League of Nations which had foundered during the war was taken up by the new organisation which sought to implant its political ideal in a more tangible reality, so that it might thereby be inspired by concrete and substantial objectives. This is one of the reasons for the existence of the dozen specialized agencies created by the family of the United Nations and dealing with Health, Culture, Agriculture, Finance, etc. Nuclear energy is one of these techniques. Becoming suddenly an important power factor and exploiting for itself the prestige of Science, it became the favorite domain for the growth of this new spirit, as much in its universal form in 1945 as in its more regional form which it was later to adopt. The achievements are numerous and of varying importance; they deserve te be studied carefully. (author) [French] L'organisation des Nations Unies et le nucleaire ont ete places simultanement, en 1945, au premier plan de la scene mondiale. La Societe des Nations ayant sombre pendant la guerre, son heritage spirituel fut recueilli par la nouvelle organisation qui chercha a enraciner son ideal politique dans une realite plus materielle, de facon a y puiser une nourriture concrete et substantielle. C'est une des raisons d'existence de la douzaine d'institutions specialisees gravitant dans la famille des Nations Unies et s'occupant de Sante, de Culture, d'Agriculture, de Finances, etc. Le nucleaire est l'une de ces techniques. Devenu soudainement un facteur primordial de puissance, Cristallisant a son benefice le prestige de la Science, c'etait un terrain de predilection pour le developpement du nouvel esprit, aussi bien sous la forme universelle de 1945, que sous les formes regionales qui ont vu le jour ensuite. Les travaux realises que nombreux, d'importance tres inegale. Ils meritent qu'on les examine

Nuclear developments at the international inter govern mental level (1961); Developpements nucleaires sur le plan international intergouvernemental (1961)

Energy Technology Data Exchange (ETDEWEB)

Waynbaum, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The United Nations organisation and nuclear energy rose simultaneously, in 1945, to occupy an important place in the public eye. The spiritual succession of the League of Nations which had foundered during the war was taken up by the new organisation which sought to implant its political ideal in a more tangible reality, so that it might thereby be inspired by concrete and substantial objectives. This is one of the reasons for the existence of the dozen specialized agencies created by the family of the United Nations and dealing with Health, Culture, Agriculture, Finance, etc. Nuclear energy is one of these techniques. Becoming suddenly an important power factor and exploiting for itself the prestige of Science, it became the favorite domain for the growth of this new spirit, as much in its universal form in 1945 as in its more regional form which it was later to adopt. The achievements are numerous and of varying importance; they deserve te be studied carefully. (author) [French] L'organisation des Nations Unies et le nucleaire ont ete places simultanement, en 1945, au premier plan de la scene mondiale. La Societe des Nations ayant sombre pendant la guerre, son heritage spirituel fut recueilli par la nouvelle organisation qui chercha a enraciner son ideal politique dans une realite plus materielle, de facon a y puiser une nourriture concrete et substantielle. C'est une des raisons d'existence de la douzaine d'institutions specialisees gravitant dans la famille des Nations Unies et s'occupant de Sante, de Culture, d'Agriculture, de Finances, etc. Le nucleaire est l'une de ces techniques. Devenu soudainement un facteur primordial de puissance, Cristallisant a son benefice le prestige de la Science, c'etait un terrain de predilection pour le developpement du nouvel esprit, aussi bien sous la forme universelle de 1945, que sous les formes regionales qui ont vu le jour ensuite. Les travaux realises que nombreux, d

Mathematical Modeling in Combustion Science

CERN Document Server

Takeno, Tadao

1988-01-01

An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

Molten salt combustion of radioactive wastes

International Nuclear Information System (INIS)

Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

1976-01-01

The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

Experimental study of improvement on combustion control of fluidized bed combustion chamber; Ryudosho shokyakuro no nenshosei no kaizen ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Izumiya, T.; Baba, K.; Koshida, H.; Uetani, J.; Furuta, M.

1998-10-29

Nippon Steel Corporation has carried out an experimental study using the Yawata waste incinerator plant in order to improve combustion control of a fluidized bed combustion chamber. For controlling the forming of dioxin, combustion control is very important in addition to conventional methods. In this paper, we report two studies about improvements on combustion control. In the first study, we verified improvement on combustion control by modifying gas flow at the freeboard. The operational results of the experiments were studied using the numerical model of the combustion chamber. The modification of gas flow at freeboard was confirmed to be effective to obtain a compact design of fluidized bed combustion chamber for municipal waste. In the second, study we improved combustion control for sewage combustion with municipal waste. In burning municipal waste and sewage, it is especially required to take combustion control into careful consideration. In this experiment, we developed a new device for supplying sewage for the appropriate controlling combustion, and verified its effectiveness to combustion control and an effective reduction of dioxin. (author)

Catalytic Combustion of Gasified Waste

Energy Technology Data Exchange (ETDEWEB)

Kusar, Henrik

2003-09-01

This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

Combustion means for solid fuels

Energy Technology Data Exchange (ETDEWEB)

Murase, D.

1987-09-23

A combustion device for solid fuel, suitable for coal, coke, charcoal, coal-dust briquettes etc., comprising:- a base stand with an opening therein, an imperforate heat resistant holding board locatable to close said opening; a combustion chamber standing on the base stand with the holding board forming the base of the combustion chamber; a wiper arm pivoted for horizontal wiping movement over the upper surface of the holding board; an inlet means at a lower edge of said chamber above the base stand, and/or in a surrounding wall of said chamber, whereby combustion air may enter as exhaust gases leave the combustion chamber; an exhaust pipe for the exhaust gases; generally tubular gas-flow heat-exchange ducting putting the combustion chamber and exhaust pipe into communication; and means capable of moving the holding board into and out of the opening for removal of ash or other residue. The invention can be used for a heating system in a house or in a greenhouse or for a boiler.

Combustion of Waste Wood. Second phase of the collaboration project on waste wood combustion

International Nuclear Information System (INIS)

Andersson, Annika; Andersson, Christer; Eriksson, Jan; Hemstroem, Bengt; Jungstedt, Jenny; Kling, Aasa; Bahr, Bo von; Ekvall, Annika; Eskilsson, David; Tullin, Claes; Harnevie, Henrik; Sieurin, Jan; Keihaes, Juha; Mueller, Christian; Berg, Magnus; Wikman, Karin

2003-08-01

Combustion of waste wood has during the last decade increased dramatically and this has resulted in a number of Swedish plants using this fuel, e.g. Handeloe P11 (Norrkoeping) and ldbaecken P3 (Nykoeping), and yet other plants that are under construction (e.g. Nynaeshamn). The experience from these plants are that waste wood combustion results in a number of operational problems. To some extent these problems are different compared with the problems related to combustion of other biofuels but the situation is not directly comparable to waste incinerators. The problems are mainly related to slagging and fouling of heat exchanger surfaces and accelerated corrosion at relatively low temperature compared to the situation for ordinary biofuels. In some cases an increase in the emissions of specific substances can also result in difficulties to fulfil the EC-directive on waste combustion. Within previous projects the main problems related to combustion of waste wood have been identified and to some extent the cause of these problems has been clarified. One result of this reported investigation is a deeper understanding of the actual causes of these problems. However, the most important result is a number of recommendations for different measures on how to achieve disturbance-free combustion of waste wood. These recommendations actually summarises the most important possible solutions on how to achieve a disturbance-free operation and a lower maintenance cost for boilers combusting waste wood and can thereby be regarded as a short summery of the whole project: 1) Improving fuel quality by Improved sorting at the source and Sieving of the fuel -> Reducing the amount of metals and chlorine and Separation of fines and thereby reducing the amount of metals. 2) Combustion modifications by Avoiding reducing conditions at the heat exchanger surfaces -> Minimising slagging, fouling and corrosion. 3) Additives or co-combustion by Addition of sulphur with the fuel; Injection of

Novel approaches in advanced combustion characterization of fuels for advanced pressurized combustion

Energy Technology Data Exchange (ETDEWEB)

Aho, M.; Haemaelaeinen, J. [VTT Energy (Finland); Joutsenoja, T. [Tampere Univ. of Technology (Finland)

1996-12-01

This project is a part of the EU Joule 2 (extension) programme. The objective of the research of Technical Research Centre of Finland (VTT) is to produce experimental results of the effects of pressure and other important parameters on the combustion of pulverized coals and their char derivates. The results can be utilized in modelling of pressurized combustion and in planning pilot-scale reactors. The coals to be studied are Polish hvb coal, French lignite (Gardanne), German anthracite (Niederberg) and German (Goettelbom) hvb coal. The samples are combusted in an electrically heated, pressurized entrained flow reactor (PEFR), where the experimental conditions are controlled with a high precision. The particle size of the fuel can vary between 100 and 300 {mu}m. The studied things are combustion rates, temperatures and sizes of burning single coal and char particles. The latter measurements are performed with a method developed by Tampere University of Technology, Finland. In some of the experiments, mass loss and elemental composition of the char residue are studied in more details as the function of time to find out the combustion mechanism. Combustion rate of pulverized (140-180 {mu}m) Gardanne lignite and Niederberg anthracite were measured and compared with the data obtained earlier with Polish hvb coal at various pressures, gas temperatures, oxygen partial pressures and partial pressures of carbon dioxide in the second working period. In addition, particle temperatures were measured with anthracite. The experimental results were treated with multivariable partial least squares (PLS) method to find regression equation between the measured things and the experimental variables. (author)

Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

Energy Technology Data Exchange (ETDEWEB)

Marriott, Craig; Gonzalez, Manual; Russell, Durrett

2011-06-30

This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables

Plasma igniter for internal-combustion engines

Science.gov (United States)

Breshears, R. R.; Fitzgerald, D. J.

1978-01-01

Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

NARCIS (Netherlands)

Khan, A.A.

2007-01-01

This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

Nuclear explosion and internal contamination; Explosion nucleaire et contamination interne

Energy Technology Data Exchange (ETDEWEB)

Aeberhardt, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

By the study of the conditions of internal contamination due to the radioactive mixture produced by a nuclear explosion, the parts played by the relative weights of the different elements and the mode of expression of the doses are considered. Only the knowledge of the weight composition of the contamination mixture and of its evolution as a function of time can provide the required basis for the study of its metabolism in the organism. The curves which give the composition of the fission product mixture - in number of nuclei - - as a function of time - have been established. These curves are applied to some practical examples, particularly relative to the nature of contamination, radiotoxicity of some elements and assessment of hazards. (author) [French] Etudiant les modalites de la contamination interne par les elements radioactifs apparus lors d'une explosion nucleaire, le role de la 'masse' et le mode d'expression des doses sont envisages. La connaissance de la composition en 'masse' du melange contaminant et de son evolution en fonction du temps peut seule apporter les bases necessaires a l'etude de son comportement dans l'organisme. Les courbes donnant la composition du melange de produits de fission - en nombre de noyaux - - en fonction du temps - ont ete etablies. Quelques applications pratiques, relatives en particulier a la nature de la contamination, a la radiotoxicite de certains elements et a l'evaluation de risque, sont envisagees a titre d'exemple. (auteur)

Combustion from basics to applications

CERN Document Server

Lackner, Maximilian; Winter, Franz

2013-01-01

Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

Combustion of diesel fuel from a toxicological perspective. I. Origin of incomplete combustion products.

Science.gov (United States)

Scheepers, P T; Bos, R P

1992-01-01

Since the use of diesel engines is still increasing, the contribution of their incomplete combustion products to air pollution is becoming ever more important. The presence of irritating and genotoxic substances in both the gas phase and the particulate phase constituents is considered to have significant health implications. The quantity of soot particles and the particle-associated organics emitted from the tail pipe of a diesel-powered vehicle depend primarily on the engine type and combustion conditions but also on fuel properties. The quantity of soot particles in the emissions is determined by the balance between the rate of formation and subsequent oxidation. Organics are absorbed onto carbon cores in the cylinder, in the exhaust system, in the atmosphere and even on the filter during sample collection. Diesel fuel contains polycyclic aromatic hydrocarbons (PAHs) and some alkyl derivatives. Both groups of compounds may survive the combustion process. PAHs are formed by the combustion of crankcase oil or may be resuspended from engine and/or exhaust deposits. The conversion of parent PAHs to oxygenated and nitrated PAHs in the combustion chamber or in the exhaust system is related to the vast amount of excess combustion air that is supplied to the engine and the high combustion temperature. Whether the occurrence of these derivatives is characteristic for the composition of diesel engine exhaust remains to be ascertained. After the emission of the particles, their properties may change because of atmospheric processes such as aging and resuspension. The particle-associated organics may also be subject to (photo)chemical conversions or the components may change during sampling and analysis. Measurement of emissions of incomplete combustion products as determined on a chassis dynamometer provides knowledge of the chemical composition of the particle-associated organics. This knowledge is useful as a basis for a toxicological evaluation of the health hazards of

Internal combustion engine

Science.gov (United States)

Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

1991-01-01

An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

KAUST Repository

Izadi Najafabadi, Mohammad

2017-11-06

A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

Energy Technology Data Exchange (ETDEWEB)

Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

2008-12-15

Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

La formation continue des usagers : évaluation qualitative des rendez-vous d'évaluation post-permis pour les conducteurs novices. Thème 11. Rapport final

OpenAIRE

CHATENET, F; TORRES, S; GAUTHIER, P; PERVANCHON, M

2001-01-01

Rapport final de convention DSCR/INRETS. Le présent rapport fait état de l'évaluation qualitative des rendez-vous d'évaluation (RVE) pour les conducteurs novices, le volet des rendez-vous de perfectionnement (RVP) pour les conducteurs expérimentés sera abordé ultérieurement dans le cadre d'une convention DSCR/INRETS. La première partie développe les problématiques et les objectifs poursuivis par cette étude ainsi que la méthodologie qui a été utilisée. Les trois autres parties présentent les...

Pressurized Fluidized Bed Combustion of Sewage Sludge

Science.gov (United States)

Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

The nuclear fuel cycle; Le cycle du combustible nucleaire

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

After a short introduction about nuclear power in the world, fission physics and the French nuclear power plants, this brochure describes in a digest way the different steps of the nuclear fuel cycle: uranium prospecting, mining activity, processing of uranium ores and production of uranium concentrates (yellow cake), uranium chemistry (conversion of the yellow cake into uranium hexafluoride), fabrication of nuclear fuels, use of fuels, reprocessing of spent fuels (uranium, plutonium and fission products), recycling of energetic materials, and storage of radioactive wastes. (J.S.)

AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

Science.gov (United States)

The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

Thermogravimetric analysis of biowastes during combustion

International Nuclear Information System (INIS)

Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

2010-01-01

The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

Straw combustion on slow-moving grates

DEFF Research Database (Denmark)

Kær, Søren Knudsen

2005-01-01

Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

Oxy-fuel combustion of solid fuels

DEFF Research Database (Denmark)

Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

2010-01-01

Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

Science.gov (United States)

Schnauffer, Kurt

1932-01-01

The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

Use of combustible wastes as fuel

Energy Technology Data Exchange (ETDEWEB)

Kotler, V.R.; Salamov, A.A.

1983-01-01

Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

Energy Technology Data Exchange (ETDEWEB)

Lu, Xingcai; Ji, Libin; Ma, Junjun; Zhou, Xiaoxin; Huang, Zhen [Key Lab. for Power Machinery and Engineering of MOE, Shanghai Jiao Tong University, 200240 Shanghai (China)

2011-02-15

This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively according to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)

Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

Science.gov (United States)

Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

2018-07-01

In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Strobes: An oscillatory combustion

NARCIS (Netherlands)

Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

2012-01-01

Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

Fifteenth combustion research conference

International Nuclear Information System (INIS)

1993-01-01

The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

Castor and Pollux - shielded cells for studying fuel treatment processes; Castor et Pollux chaines blindees d'etudes de procedes de traitement de combustibles

Energy Technology Data Exchange (ETDEWEB)

Faudot, G; Bathellier, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

CASTOR and POLLUX, two alpha, beta, gamma cells are described in the present paper. They are located in the CEN at Fontenay-aux-Roses (France). They are designed for improvement studies of the various aqueous separation processes used in irradiated fuels reprocessing plants. Located in the same air-tight steel encasement, they arc inter-connected by a pneumatic transfer. These two cells have a similar in-line conception and they include: a gamma shielding in lead of 10 cm of thickness; an inner air-tight box, made with stainless steel and plexiglas, is maintained in lowering in comparison to room pressure. Eleven Hobson model seven master-slave manipulators allow inner manipulations. Then the inner equipment is described briefly. (author) [French] Le present document decrit les cellules alpha, beta, gamma CASTOR et POLLUX edifiees au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Elles sont destinees aux etudes visant a l'amelioration des procedes de separation par voie aqueuse utilises dans les usines de retraitement des combustibles irradies. Ces deux chaines, implantees dans le meme caisson et reliees par convoyeur pneumatique, sont de conception identique et comprennent: une protection biologique constituee par 10 cm d'epaisseur de plomb; une enceinte interieure etanche alpha, en acier inoxidable et plexiglas, maintenue en depression. Des telemanipulateurs Hobson, modele 7, permettent les manipulations interieures. On decrit ensuite brievement les installations annexes. (auteur)

Numerical analysis for controlling mixture heterogeneity to reduce abrupt combustion in diesel PCCI combustion

Energy Technology Data Exchange (ETDEWEB)

Nishiwaki, Kazuie [Ritsumeikan University (Japan); Kojima, Takafumi [Takamatsu National College of Technology (Japan)

2010-07-01

In the energy sector, stringent regulations have been implemented on combustion emissions in order to address health and environmental concerns and help improve air quality. A novel combustion mode, premixed charge compression ignition (PCCI), can improve the emissions performance of an engine over that of conventional diesel. The aim of this research is to develop a model to analyze the mixture formation in the PCCI combustion mode. A numerical model was developed and was applied to an engine and the results were compared to experimental results. It was found that the model results are in agreement with the experimental results. This paper presented a novel LES computer model and demonstrated that it is efficient in predicting the mixture formation in the PCCI combustion mode.

Modeling and simulating combustion and generation of NOx

International Nuclear Information System (INIS)

Lazaroiu, Gheorghe

2007-01-01

This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion. (author)

Multi-zone modelling of PCCI combustion

NARCIS (Netherlands)

Egüz, U.; Somers, L.M.T.; Leermakers, C.A.J.; Goey, de L.P.H.

2011-01-01

Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) combustion is a promising concept for the diesel combustion. Although EDI PCCI assures very low soot and NO xemission levels, the injection is uncoupled from combustion, which narrows down the operating conditions. The main

Combustor nozzle for a fuel-flexible combustion system

Science.gov (United States)

Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

2011-03-22

A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

Establishment of Combustion Model for Isooctane HCCI Marine Diesel Engine and Research on the Combustion Characteristic

Directory of Open Access Journals (Sweden)

Li Biao

2016-01-01

Full Text Available The homogeneous charge compression ignition (HCCI combustion mode applied in marine diesel engine is expected to be one of alternative technologies to decrease nitrogen oxide (NOX emission and improve energy utilization rate. Applying the chemical-looping combustion (CLC mechanism inside the cylinder, a numerical study on the HCCI combustion process is performed taking a marine diesel engine as application object. The characteristic feature of combustion process is displayed. On this basis, the formation and emission of NOX are analyzed and discussed. The results indicate that the HCCI combustion mode always exhibit two combustion releasing heats: low-temperature reaction and high-temperature reaction. The combustion phase is divided into low-temperature reaction zone, high-temperature reaction zone and negative temperature coefficient (NTC zone. The operating conditions of the high compression ratio, high intake air temperature, low inlet pressure and small excess air coefficient would cause the high in-cylinder pressure which often leads engine detonation. The low compression ratio, low intake air temperature and big excess air coefficient would cause the low combustor temperature which is conducive to reduce NOX emissions. These technological means and operating conditions are expected to meet the NOX emissions limits in MARPOL73/78 Convention-Annex VI Amendment.

Emission and combustion characteristics of multiple stage diesel combustion; Nidan nensho ni yoru diesel kikan no nensho to haishutsubutsu tokusei

Energy Technology Data Exchange (ETDEWEB)

Hashizume, T; Miyamoto, T; Tsujimura, K [New A.C.E. Institute Co. Ltd., Tokyo (Japan); Kobayashi, S; Shimizu, K [Japan Automobile Research Institute, Tsukuba (Japan)

1997-10-01

A new concept of multiple stage diesel combustion was studied by means of engine test, combustion observation and numerical simulation, in order to reduce NOx emissions at high load conditions. With this concept, the premixed combustion occurs under the fuel lean conditions and the diffusion combustion occurs under the high temperature conditions. As seen in the result of combustion observation, a first stage combustion occurs with no luminous flame. A second stage combustion occurs with a luminous flame after very short ignition delay period. However the luminous flame is disappeared immediately. Because cylinder temperature is high, and hence soot oxidizes immediately. 5 refs., 11 figs., 1 tab.

76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

Science.gov (United States)

2011-03-24

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc.), Collectible Concepts Group, Inc., Communitronics of... is a lack of current and accurate information concerning the securities of Clean Energy Combustion...

Effect of combustion characteristics on wall radiative heat flux in a 100 MWe oxy-coal combustion plant

Energy Technology Data Exchange (ETDEWEB)

Park, S.; Ryu, C. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Chae, T.Y. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Yang, W. [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Kim, Y.; Lee, S.; Seo, S. [Korea Electric Power Research Institute (KEPRI), Daejeon (Korea, Republic of). Power Generation Lab.

2013-07-01

Oxy-coal combustion exhibits different reaction, flow and heat transfer characteristics from air-coal combustion due to different properties of oxidizer and flue gas composition. This study investigated the wall radiative heat flux (WRHF) of air- and oxy-coal combustion in a simple hexahedral furnace and in a 100 MWe single-wall-fired boiler using computational modeling. The hexahedral furnace had similar operation conditions with the boiler, but the coal combustion was ignored by prescribing the gas properties after complete combustion at the inlet. The concentrations of O{sub 2} in the oxidizers ranging between 26 and 30% and different flue gas recirculation (FGR) methods were considered in the furnace. In the hexahedral furnace, the oxy-coal case with 28% of O{sub 2} and wet FGR had a similar value of T{sub af} with the air-coal combustion case, but its WRHF was 12% higher. The mixed FGR case with about 27% O{sub 2} in the oxidizer exhibited the WRHF similar to the air-coal case. During the actual combustion in the 100 MWe boiler using mixed FGR, the reduced volumetric flow rates in the oxy-coal cases lowered the swirl strength of the burners. This stretched the flames and moved the high temperature region farther to the downstream. Due to this reason, the case with 30% O{sub 2} in the oxidizers achieved a WRHF close to that of air-coal combustion, although its adiabatic flame temperature (T{sub af}) and WHRF predicted in the simplified hexahedral furnace was 103 K and 10% higher, respectively. Therefore, the combustion characteristics and temperature distribution significantly influences the WRHF, which should be assessed to determine the ideal operating conditions of oxy- coal combustion. The choice of the weighted sum of gray gases model (WSGGM) was not critical in the large coal-fired boiler.

Infrared monitoring of combustion

International Nuclear Information System (INIS)

Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

1991-01-01

In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

Control device for combustible gas concentration

International Nuclear Information System (INIS)

Osawa, Yasuo.

1988-01-01

Purpose: To control the concentration of combustible gases such as hydrogen evolved in a reactor container upon loss-of-coolant accidents. Constitution: Combustible gases evolved from the lower area of a drywell in which a combustible atmosphere is liable to be formed locally are taken out through a take-out pipeway to the outside of a reactor container and processed by a hydrogen-oxygen recombiner. Combustible gases in other areas of the drywell are also introduced to the lower area of the drywell and then taken-out externally for procession. Further, combustible gases in the suppression chamber are introduced by the opening of a vacuum breaking valve through a gas supply pipe to the lower area of the drywell and fluids in the drywell are stirred and diluted with fluids exhausted from the gas supply pipe. Disposition of such take-out pipeway and gas supply pipe can reduce the possibility of forming local combustible atmosphere to improve the integrity of the reactor container. (Kamimura, M.)

Techniques de combustion Combustin Techniques

Directory of Open Access Journals (Sweden)

Perthuis E.

2006-11-01

Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

PDF Modeling of Turbulent Combustion

National Research Council Canada - National Science Library

Pope, Stephen B

2006-01-01

.... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

Sulfur Chemistry in Combustion I

DEFF Research Database (Denmark)

Johnsson, Jan Erik; Glarborg, Peter

2000-01-01

of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

In situ high-temperature gas sensors: continuous monitoring of the combustion quality of different wood combustion systems and optimization of combustion process

Directory of Open Access Journals (Sweden)

H. Kohler

2018-03-01

Full Text Available The sensing characteristics and long-term stability of different kinds of CO ∕ HC gas sensors (non-Nernstian mixed potential type during in situ operation in flue gas from different types of low-power combustion systems (wood-log- and wood-chip-fuelled were investigated. The sensors showed representative but individual sensing behaviour with respect to characteristically varying flue gas composition over the combustion process. The long-term sensor signal stability evaluated by repeated exposure to CO ∕ H2 ∕ N2 ∕ synthetic air mixtures showed no sensitivity loss after operation in the flue gas. Particularly for one of the sensors (Heraeus GmbH, this high signal stability was observed in a field test experiment even during continuous operation in the flue gas of the wood-chip firing system over 4 months. Furthermore, it was experimentally shown that the signals of these CO ∕ HC sensing elements yield important additional information about the wood combustion process. This was demonstrated by the adaptation of an advanced combustion airstream control algorithm on a wood-log-fed fireplace and by the development of a combustion quality monitoring system for wood-chip-fed central heaters.

Report on the possibilities of long-term storage of irradiated nuclear fuels; Rapport sur les possibilites d'entreposage a long terme de combustibles nucleaires irradies

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This report aims at giving a legislative aspect to the many rules that govern the activities of the back-end of the fuel cycle in France. These activities concern the unloading of spent nuclear fuels, their reprocessing, storage, recycling and definitive disposal. The following points are reviewed and commented: the management of non-immediately reprocessed fuels (historical reasons of the 'all wastes reprocessing' initial choice, evolution of the economic and political context, the future reprocessing or the definitive disposal of spent fuels in excess); the inevitable long-term storage of part of the spent fuels (quantities and required properties of long-term stored fuels, the eventuality of a definitive disposal of spent fuels); the criteria that long-term storage facilities must fulfill (confinement measures, reversibility, surveillance and control during the whole duration of the storage); storage concept to be retained (increase of storage pools capacity, long-term storage in pools of reprocessing plants, centralized storage in pools, surface dry-storage on power plant sites, reversible underground storage, subsurface storage and storage/disposal in galleries, surface dry-storage facilities); the preliminary studies for the creation of long-term storage facilities (public information, management by a public French organization, clarifying of the conditions of international circulation of spent fuels); problems linked with the presence of foreign spent fuels in France (downstream of the reprocessing cycle, foreign plutonium and wastes re-shipment); conclusions and recommendations. (J.S.)

Installation and testing of the 150keV high current pulsed accelerator installed at the Service de Physique Nucleaire in Bruyeres-le-Chatel

International Nuclear Information System (INIS)

Dandine, Andre; Sinopoli, Louis.

1976-01-01

A 150keV accelerator installed at the Service de Physique Nucleaires in Bruyeres-le-Chatel is described which has been equipped especially for the preparation of the nuclear experiments carried out with the EN 7MV tandem Van de Graaff, and for the completion of totally independent experiments. Details of the ion optical arrangement and the pulsing system are presented; unanalysed beams of intensity 1 to 2mA are obtained accelerating either protons or deuterons. In the pulsed mode, at 1.25 MHz or 2.5MHz, the average intensity of the analysed beam is 8 to 10μA and the pulse length is 2ns [fr

Internal and surface phenomena in metal combustion

Science.gov (United States)

Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

1995-01-01

Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

Second law comparison of oxy-fuel combustion and post-combustion carbon dioxide separation

International Nuclear Information System (INIS)

Simpson, Adam P.; Simon, A.J.

2007-01-01

To define 2nd law efficiency targets for novel separation technologies, a simplified model of a power plant with two forms of CO 2 capture was developed. In this investigation, oxy-fuel combustion and post-combustion CO 2 separation were compared on an exergetic basis. Using exergy balances and black-box models of power plant components, multiple scenarios were run to determine the impact of plant configuration and separation unit efficiency on overall plant performance. Second law efficiency values from the literature were used to set the baseline performance of various CO 2 separation configurations. Assumed advances in 2nd law efficiency were used to determine the potential for overall system performance improvement. It was found that the 2nd law efficiency of air separation must reach a critical value before the thermodynamics of oxy-fuel combustion become favorable. Changes in operating equivalence ratio significantly move the tipping-point between post-combustion and oxy-fuel strategies

Investigating co-combustion characteristics of bamboo and wood.

Science.gov (United States)

Liang, Fang; Wang, Ruijuan; Jiang, Changle; Yang, Xiaomeng; Zhang, Tao; Hu, Wanhe; Mi, Bingbing; Liu, Zhijia

2017-11-01

To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

New technologies reducing emissions from combustion of biofuels

International Nuclear Information System (INIS)

Oravainen, H.

1997-01-01

In reducing CO 2 emissions, bioenergy will be the most important source of renewable energy in the next few decades. In principle, combustion of biomass is friendly to the environment because CO 2 released during combustion is recycled back into natural circulation. Biofuels normally contain little nitrogen and sulphur. However, depending on the combustion technology used, emissions may be quite high. This is true of combustion of biomass fuels in small appliances like wood stoves, fireplaces, small boilers etc. When fuels having high content of volatile matter are burnt in appliances using batch type combustion, the process is rather an unsteady-state combustion. Emissions of carbon monoxide, other combustible gases and particulates are quite difficult to avoid. With continuous combustion processes this is not normally a problem. This conference paper presents some means of reducing emissions from combustion of biofuels. 5 refs., 4 figs

Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

Science.gov (United States)

Guo, Feihong; Zhong, Zhaoping

2018-08-01

This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

KAUST Repository

Vallinayagam, R.

2018-03-20

The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

Comparison of different chemical kinetic mechanisms of methane combustion in an internal combustion engine configuration

OpenAIRE

Ennetta Ridha; Hamdi Mohamed; Said Rachid

2008-01-01

Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion...

Burning Questions in Gravity-Dependent Combustion Science

Science.gov (United States)

Urban, David; Chiaramonte, Francis P.

2012-01-01

Building upon a long history of spaceflight and ground based research, NASA's Combustion Science program has accumulated a significant body of accomplishments on the ISS. Historically, NASAs low-gravity combustion research program has sought: to provide a more complete understanding of the fundamental controlling processes in combustion by identifying simpler one-dimensional systems to eliminate the complex interactions between the buoyant flow and the energy feedback to the reaction zone to provide realistic simulation of the fire risk in manned spacecraft and to enable practical simulation of the gravitational environment experienced by reacting systems in future spacecraft. Over the past two decades, low-gravity combustion research has focused primarily on increasing our understanding of fundamental combustion processes (e.g. droplet combustion, soot, flame spread, smoldering, and gas-jet flames). This research program was highly successful and was aided by synergistic programs in Europe and in Japan. Overall improvements were made in our ability to model droplet combustion in spray combustors (e.g. jet engines), predict flame spread, predict soot production, and detect and prevent spacecraft fires. These results provided a unique dataset that supports both an active research discipline and also spacecraft fire safety for current and future spacecraft. These experiments have been conducted using the Combustion Integrated Rack (CIR), the Microgravity Science Glovebox and the Express Rack. In this paper, we provide an overview of the earlier space shuttle experiments, the recent ISS combustion experiments in addition to the studies planned for the future. Experiments in combustion include topics such as droplet combustion, gaseous diffusion flames, solid fuels, premixed flame studies, fire safety, and super critical oxidation processes.

General problems arising from the analogical resolution of the kinetic equations of nuclear reactors (1961); Problemes generaux poses par la resolution analogique des equations cinetiques des reacteurs nucleaires (1961)

Energy Technology Data Exchange (ETDEWEB)

Caillet, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The author reviews precisely the analogical techniques used for the resolution of the kinetic equations of nuclear reactors. Prior to this, he recalls the reasons which oblige physicians and engineers, even today, to use electronic machines in this domain. The author then considers the technological problems posed by the range of values which the various nuclear parameters adopt. In each case, he shows that a compromise is possible allowing an optimum precision. He compares the results to those obtained by arithmetic calculation and uses the examples chosen in a critical analysis of the present possibilities of the two methods of calculation. (author) [French] L'auteur cherche a faire un point aussi exact que possible des techniques analogiques utilisees pour resoudre les equations cinetiques des reacteurs nucleaires. Il rappelle auparavant les raisons pour lesquelles physiciens et ingenieurs sont obliges, encore aujourd'hui, de faire appel aux machines electroniques dans ce domaine. Puis il etudie les problemes technologiques que souleve le champ des valeurs prises par les differents parametres nucleaires. Dans chacun des cas, il montre l'existence d'un compromis qui permet d'atteindre une precision optimum. Il compare les resultats obtenus a ceux provenant de calculateurs arithmetiques et profite des exemples choisis pour faire une analyse critique des possibilites actuelles offertes par les deux modes de calcul. (auteur)

Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

Energy Technology Data Exchange (ETDEWEB)

Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

2011-04-15

The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

Catalytically enhanced combustion process

International Nuclear Information System (INIS)

Rodriguez, C.

1992-01-01

This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

International Nuclear Information System (INIS)

Chen, Zheng; Yang, Feng; Xue, Shuo; Wu, Zhenkuo; Liu, Jingping

2015-01-01

Highlights: • Effects of 0–50% n-butanol addition on GDI engine are experimentally studied. • Higher n-butanol fractions increase combustion pressure and fasten burning rate. • Higher n-butanol fractions increase BSFC but improve BTE. • Higher n-butanol fractions enhance combustion stability but increase knock intensity. • Higher n-butanol fractions reduce exhaust temperature and NOx emissions. - Abstract: An experimental study was carried out on a turbocharged gasoline direct injection (GDI) engine fueled by n-butanol/gasoline blends. Effects of n-butanol percents (15%, 30%, and 50%) on combustion and performance of the engine operating on stoichiometric combustion condition were discussed and also compared with pure gasoline in this paper. The results indicate that n-butanol/gasoline blends increase combustion pressure and pressure rise rate, fasten burning rate, and shorten ignition delay and combustion duration, as compared to pure gasoline. Moreover, these trends are impacted more evidently with increased n-butanol fraction in the blends. In addition, higher n-butanol percent of gasoline blends increase combustion temperature but decrease the temperature in the later stage of expansion stroke, which contributes to the control of exhaust temperature at high-load. With regards to engine performance, higher n-butanol percent in the blends results in increased brake specific fuel consumption (BSFC) and higher brake thermal efficiency (BTE). However, higher n-butanol addition helps to improve combustion stability but shows slightly higher knock possibility in high-load. In that case, the knock trend could be weakened by retarding ignition timing. Moreover, higher n-butanol addition significantly decreases NOx emissions, but it increases CO emissions obviously.

Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

KAUST Repository

Jing, Wei; Roberts, William L.; Fang, Tiegang

2015-01-01

This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2

Study and installation of concrete shielding in the civil engineering of nuclear construction (1960); Etude et mise en place des betons de protection dans le genie civil des ouvrages nucleaires (1960)

Energy Technology Data Exchange (ETDEWEB)

Dubois, F. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The object of this report is to give technical information about high density concretes which have become very important for radiation biological shielding. The most generally used heavy aggregates (barytes, ilmenite, ferrophosphorus, limonite, magnetite and iron punching) to make these concretes are investigated from the point of view prospecting and physical and chemical characteristics. At first, a general survey of shielding concretes is made involving the study of components, mixing and placing methods, then, a detailed investigation of some high density concretes: barytes concrete, with incorporation of iron punching or iron shot, ferrophosphorus concrete, ilmenite concrete and magnetite concrete, more particularly with regard to grading and mix proportions and testing process. To put this survey in concrete form, two practical designs are described such as they have been carried out at the Saclay Nuclear Station. Specifications are given for diverse concretes and for making the proton-synchrotron 'Saturne' shielding blocks. (author) [French] Ce rapport a pour objet de donner des precisions techniques au sujet des betons a haute densite qui ont pris une grande importance pour la protection biologique contre les rayonnements. Les agregats lourds les plus couramment utilises (barytine, ilmenite, ferrophosphore, limonite, magnetite et riblons) pour la fabrication de ces betons, sont examines du point de vue prospection et caracteristiques physiques et chimiques. On procede d'abord a une etude generale des betons de protection comprenant l'etude des constituants, de la confection et de la mise en place, ensuite, a un examen detaille de quelques betons a haute densite: betons a base de barytine, avec incorporation de riblons ou de grenaille de fonte, betons au ferrophosphore, a base d'ilmenite ou de magnetite, notamment en ce qui concerne la granulometrie, la composition, le dosage et les processus d'essais. Pour concretiser ces

Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

International Nuclear Information System (INIS)

Bělohradský, Petr; Skryja, Pavel; Hudák, Igor

2014-01-01

This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NO x type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NO x ) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NO x emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NO x emission was below 120 mg/Nm 3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO 2 and H 2 O. The available heat at 46% O 2 was higher by 20% compared with that at 21% O 2 . - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NO x increased sharply as oxygen concentration increased during PE tests. • NO x was below 120 mg/Nm 3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O 2 concentration was increased. • OEC flames were observed stable, more luminous and

Rapport sur l’affaire Darrieussecq // Report on the Darrieussecq affair

Directory of Open Access Journals (Sweden)

Judit Lipták-Pikó

2015-12-01

Full Text Available Marie Darrieussecq, a contemporary French writer, had been accused of plagiarism several times during her career. Besides defending her reputation, these accusations forced her to think about her conceptions on fiction and writing. Finally, in Rapport de police, she succeeded in showing a mirror to the society of contemporary French writers, in which a tendency towards denying the legitimacy of fiction in certain cases can be observed. This phenomenon is diagnosed by Tiphaine Samoyault as the extension of the domain of plagiarism on simple particles of life. Behind this tendency resurges the old controversy of Plato and Aristotle on mimesis and fiction. Along with Jean-Marie Schaeffer’s analysis on the function of fiction from a cognitive point of view unfolds an apology for lecture and for a fictional writing that is capable of saying the inexpressible and speak for those who don’t have access to language.

RAPPORT: running scientific high-performance computing applications on the cloud.

Science.gov (United States)

Cohen, Jeremy; Filippis, Ioannis; Woodbridge, Mark; Bauer, Daniela; Hong, Neil Chue; Jackson, Mike; Butcher, Sarah; Colling, David; Darlington, John; Fuchs, Brian; Harvey, Matt

2013-01-28

Cloud computing infrastructure is now widely used in many domains, but one area where there has been more limited adoption is research computing, in particular for running scientific high-performance computing (HPC) software. The Robust Application Porting for HPC in the Cloud (RAPPORT) project took advantage of existing links between computing researchers and application scientists in the fields of bioinformatics, high-energy physics (HEP) and digital humanities, to investigate running a set of scientific HPC applications from these domains on cloud infrastructure. In this paper, we focus on the bioinformatics and HEP domains, describing the applications and target cloud platforms. We conclude that, while there are many factors that need consideration, there is no fundamental impediment to the use of cloud infrastructure for running many types of HPC applications and, in some cases, there is potential for researchers to benefit significantly from the flexibility offered by cloud platforms.

Combustion modeling in waste tanks

International Nuclear Information System (INIS)

Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

1997-01-01

This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

Ignition and wave processes in combustion of solids

CERN Document Server

Rubtsov, Nickolai M; Alymov, Michail I

2017-01-01

This book focuses on the application of classical combustion theory to ignition and flame propagation in solid-solid and gas-solid systems. It presents experimental investigations in the areas of local ignition, filtration combustion, self-propagating high temperature synthesis and nanopowders protection. The authors highlight analytical formulas used in different areas of combustion in solids and propose an approach based on classical combustion theory. The book attempts to analyze the basic approaches to understanding of solid-solid and solid - gas combustion presented in contemporary literature in a unified approach based on classical combustion theory. .

Effects of stepwise gas combustion on NOx generation

International Nuclear Information System (INIS)

Woperane Seredi, A.; Szepesi, E.

1999-01-01

To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

Fuel Combustion and Engine Performance | Transportation Research | NREL

Science.gov (United States)

Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

A + (B[subscript 1]) Professor--student Rapport + (B[subscript 2]) Humor + (B[subscript 3]) Student Engagement = (Y) Student Ratings of Instructors

Science.gov (United States)

Richmond, Aaron S.; Berglund, Majken B.; Epelbaum, Vadim B.; Klein, Eric M.

2015-01-01

Teaching effectiveness is often evaluated through student ratings of instruction (SRI). Research suggests that there are many potential factors that can predict student's perceptions of teaching effectiveness such as professor-student rapport, student engagement, and perceived humor of the instructor. Therefore, we sought to assess whether…

Specifics of phytomass combustion in small experimental device

Science.gov (United States)

Lenhard, Richard; Mičieta, Jozef; Jandačka, Jozef; Gavlas, Stanislav

2015-05-01

A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass), which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

Specifics of phytomass combustion in small experimental device

Directory of Open Access Journals (Sweden)

Lenhard Richard

2015-01-01

Full Text Available A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass, which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

Dosimeter calibration facilities and methods at the Radiation Measurement Laboratory of the Centre d'etudes nucleaires, Grenoble

International Nuclear Information System (INIS)

Choudens, H. de; Herbaut, Y.; Haddad, A.; Giroux, J.; Rouillon, J.; CEA Centre d'Etudes Nucleaires de Grenoble, 38

1975-01-01

At the Centre d'etudes nucleaires, Grenoble, the Radiation Measurement Laboratory, which forms part of the Environmental Protection and Research Department, serves the entire Centre for purposes of dosimetry and the calibration of dose meters. The needs of radiation protection are such that one must have facilities for checking periodically the calibration of radiation-monitoring instruments and developing special dosimetry techniques. It was thought a good idea to arrange for the dosimetry and radiation protection team to assist other groups working at the Centre - in particular, the staff of the biology and radiobiology laboratories - and also bodies outside the framework of the French Commissariat a l'energie atomique. Thus, technical collaboration has been established with, for example, Grenoble's Centre hospitalier universitaire (university clinic), which makes use of the facilities and skills available at the Radiation Measurement Laboratory for solving special dosimetry problems. With the Laboratory's facilities it is possible to calibrate dose meters for gamma, beta and neutron measurements

Traveling-Wave Thermoacoustic Engines With Internal Combustion

Science.gov (United States)

Weiland, Nathan Thomas; Zinn, Ben T.; Swift, Gregory William

2004-05-11

Thermoacoustic devices are disclosed wherein, for some embodiments, a combustion zone provides heat to a regenerator using a mean flow of compressible fluid. In other embodiments, burning of a combustible mixture within the combustion zone is pulsed in phase with the acoustic pressure oscillations to increase acoustic power output. In an example embodiment, the combustion zone and the regenerator are thermally insulated from other components within the thermoacoustic device.

Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

Directory of Open Access Journals (Sweden)

BORISLAV GRUBOR

2003-02-01

Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

Rapport sur le développement dans le monde sur le thème du rôle ...

International Development Research Centre (IDRC) Digital Library (Canada)

... rural et sont tributaires principalement de l'agriculture pour assurer leur subsistance. Ce projet permettra de veiller à ce qu'une place soit accordée aux travaux de recherche financés par le CRDI, aux points de vue différents et aux auteurs de l'hémisphère Sud dans le Rapport sur le développement dans le monde 2008.

"Let Me Tell You About My…" Provider Self-Disclosure in the Emergency Department Builds Patient Rapport.

Science.gov (United States)

Zink, Korie L; Perry, Marcia; London, Kory; Floto, Olivia; Bassin, Benjamin; Burkhardt, John; Santen, Sally A

2017-01-01

As patients become increasingly involved in their medical care, physician-patient communication gains importance. A previous study showed that physician self-disclosure (SD) of personal information by primary care providers decreased patient rating of the provider communication skills. The objective of this study was to explore the incidence and impact of emergency department (ED) provider self-disclosure on patients' rating of provider communication skills. A survey was administered to 520 adult patients or parents of pediatric patients in a large tertiary care ED during the summer of 2014. The instrument asked patients whether the provider self-disclosed and subsequently asked patients to rate providers' communication skills. We compared patients' ratings of communication measurements between encounters where self-disclosure occurred to those where it did not. Patients reported provider SD in 18.9% of interactions. Provider SD was associated with more positive patient perception of provider communication skills (pself-disclosure (47.1%). Patients reported that they would like to hear about their providers' experiences with a similar chief complaint (64.4% of patients), their providers' education (49%), family (33%), personal life (21%) or an injury/ailment unlike their own (18%). Patients responded that providers self-disclose to make patients comfortable/at ease and to build rapport. Provider self-disclosure in the ED is common and is associated with higher ratings of provider communication, rapport, and patient satisfaction.

The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

Science.gov (United States)

Dickey, Daniel W.; Vinyard, Shannon; Keribar, Rifat

1988-01-01

The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide emissions. The unburned hydrocarbon emissions were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine.

Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

NARCIS (Netherlands)

Leskens, M.

2013-01-01

The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

Toxicology of Biodiesel Combustion products

Science.gov (United States)

1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

Producer for vegetal combustibles for internal-combustion motors

Energy Technology Data Exchange (ETDEWEB)

1943-12-28

A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

Annual report ''nuclear safety in France''; Le rapport annuel ''la surete nucleaire en France''

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

This document is the 2001 annual report of the French authority of nuclear safety (ASN). It summarizes the highlights of the year 2000 and details the following aspects: the nuclear safety in France, the organization of the control of nuclear safety, the regulation relative to basic nuclear facilities, the control of facilities, the information of the public, the international relations, the organisation of emergencies, the radiation protection, the transport of radioactive materials, the radioactive wastes, the PWR reactors, the experimental reactors and other laboratories and facilities, the nuclear fuel cycle facilities, and the shutdown and dismantling of nuclear facilities. (J.S.)

Information report nuclear energy in Europe; Rapport d'information energie nucleaire en Europe

Energy Technology Data Exchange (ETDEWEB)

Montesquiou, A. de

2002-07-01

This report takes stock on the nuclear energy situation in Europe. The European Union with more than 40% of the nuclear power capacity in the world, is already confronted with the nuclear energy place and stakes in the future energy policy. The report si presented in two main parts. The first part, ''the assets and the weaknesses of the nuclear energy'', deals with the economical aspects which historically based the choice of the nuclear energy and the induced impacts on the environment. The competitiveness of the nuclear energy but also the wastes management problem are discussed. The second part, ''the diplomatic and juridical framework of the nuclear energy development'', details and presents the limits of the EURATOM treaty. (A.L.B.)

Progress report for 94/95; Institut des Sciences Nucleaires - Rapport d`activite 1994-1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-12-31

We find here the progress report for the two years 1994 and 1995 for institute of nuclear sciences at Grenoble. In the field of quarks and leptons, three teams are invested in CERN programmes: A.T.L.A.S. near the L.H.C., D.E.L.P.H.I; the neutrino team has achieved the building of the detector in the M.U.N.U. collaboration. In the theme Hadrons physics we have G.R.A.A.L. at E.S.R.F., C.E.B.A.F. and W.A.89. Physicists are implied in the project E.L.F.E at D.E.S.Y. The study of superdeformed states go on with E.U.R.O.G.R.A.M. New techniques have been used near the programme S.A.R.A. The programme P.I.A.F.E. saw the resolution of the difficult problem of the transformation 1+ gives N+ ions of 30 KeV and their transport on long distances. The team of hybrid reactors have shown that it was possible to amplify energy by a sub critical accelerator-reactor hybrid system, experience initiated by C. Rubbia at C.E.R.N. (N.C.).

Progress report for 94/95; Institut des Sciences Nucleaires - Rapport d`activite 1994-1995

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

We find here the progress report for the two years 1994 and 1995 for institute of nuclear sciences at Grenoble. In the field of quarks and leptons, three teams are invested in CERN programmes: A.T.L.A.S. near the L.H.C., D.E.L.P.H.I; the neutrino team has achieved the building of the detector in the M.U.N.U. collaboration. In the theme Hadrons physics we have G.R.A.A.L. at E.S.R.F., C.E.B.A.F. and W.A.89. Physicists are implied in the project E.L.F.E at D.E.S.Y. The study of superdeformed states go on with E.U.R.O.G.R.A.M. New techniques have been used near the programme S.A.R.A. The programme P.I.A.F.E. saw the resolution of the difficult problem of the transformation 1+ gives N+ ions of 30 KeV and their transport on long distances. The team of hybrid reactors have shown that it was possible to amplify energy by a sub critical accelerator-reactor hybrid system, experience initiated by C. Rubbia at C.E.R.N. (N.C.).

Report transparency and nuclear safety 2007 - CISBIO; Rapport transparence et securite nucleaire 2007 - CISBIO

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-07-01

This report presents the activities of CISBIO, nuclear base installation, for the year 2007. CISBIO realizes at Saclay most of the radiopharmaceuticals and drugs distributed in France for the nuclear medicine. The actions concerning the safety, the radiation protection, the significant events, the release control and the environmental impacts and the wastes stored on the center are discussed. (A.L.B.)

Investigation of bluff-body micro-flameless combustion

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

2014-01-01

Highlights: • The temperature uniformity of the micro-flameless combustion increases when a triangular bluff-body is applied. • The velocity and temperature of exhaust gases are higher in micro-flameless combustion compared to the conventional mode. • The rate of fuel–oxidizer consumption in micro-flameless mode is lower than conventional micro-combustion. - Abstract: Characteristics of lean premixed conventional micro-combustion and lean non-premixed flameless regime of methane/air are investigated in this paper by solving three-dimensional governing equations. At moderate equivalence ratio (∅ = 0.5), standard k–ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models. The effect of bluff-body on the temperature distribution of both conventional and flameless mode is developed. The results show that in the premixed conventional micro-combustion the stability of the flame is increased when a triangular bluff-body is applied. Moreover, micro-flameless combustion is more stable when bluff-body is used. Micro-flameless mode with bluff-body and 7% O 2 concentration (when N 2 is used as diluent) illustrated better performance than other cases. The maximum temperature in premixed conventional micro-combustion and micro-flameless combustion was recorded 2200 K and 1520 K respectively. Indeed, the flue gas temperature of conventional mode and flameless combustion was 1300 K and 1500 K respectively. The fluctuation of temperature in the conventional micro-combustor wall has negative effects on the combustor and reduces the lifetime of micro-combustor. However, in the micro-flameless mode, the wall temperature is moderate and uniform. The rate of fuel–oxidizer consumption in micro-flameless mode takes longer time and the period of cylinders recharging is prolonged

Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines

International Nuclear Information System (INIS)

Su, LiWang; Li, XiangRong; Zhang, Zheng; Liu, FuShui

2014-01-01

Highlights: • A new combustion system named FSCS for DI diesel engines was proposed. • Fuel/air mixture formation was improved for the application of FSCS. • The FSCS showed a good performance on emission characteristics. - Abstract: To optimize the fuel/air mixture formation and improve the environmental effect of direct injection (DI) diesel engines, a new forced swirl combustion system (FSCS) was proposed concerned on unique design of the geometric shape of the combustion chamber. Numerical simulation was conducted to verify the combustion and emission characteristics of the engines with FSCS. The fuel/air diffusion, in-cylinder velocity distribution, turbulent kinetic energy and in-cylinder temperature distribution were analyzed and the results shown that the FSCS can increase the area of fuel/air diffusion and improve the combustion. The diesel engine with FSCS also shown excellent performance on emission. At full load condition, the soot emission was significantly reduced for the improved fuel/air mixture formation. There are slightly difference for the soot and NO emission between the FSCS and the traditional omega combustion system at lower load for the short penetration of the fuel spray

Combustion & Laser Diagnostics Research Complex (CLDRC)

Data.gov (United States)

Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

Transistorized wide band pulse amplifier; Amplificateur d'impulsions a large bande et a transistors

Energy Technology Data Exchange (ETDEWEB)

Girard, J; Savinelli, H [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Hazoni, Y [Atomic Energy Commission (Israel)

1960-07-01

A simple wide band amplifier is described below, having a stability better than 1{sup 0}/00 deg{sup -1} centigrade, a current gain of 10{sup 3}, bandwidth of 30 MHz, and a signal to noise current ratio of about 100. This amplifier has been studied to answer the necessity of a fast transistor head amplifier for nuclear detectors, having in mind pile up and overloading problems. (author) [French] Un amplificateur simple, a large bande, est decrit ci-apres, il a une stabilite meilleure que le 0/00 par degre centigrade, un gain en courant de 10{sup 3} une largeur de bande de 30 MHz, et un rapport signal sur bruit en courant d'environ 100. Cet amplificateur a ete etudie pour repondre a la necessite de l'amplification des impulsions provenant de detecteurs nucleaires, ayant a l'esprit les problemes d'empilement et de saturation. (auteur)

The rheodynamics and combustion of coal-water mixtures

Energy Technology Data Exchange (ETDEWEB)

Burdukov, A.P.; Popov, V.I.; Tomilov, V.G.; Fedosenko, V.D. [Russian Academy of Science, Novosibirsk (Russian Federation). Inst. of Thermophysics (Siberian Branch, Russian Academy of Science)

2002-05-01

Investigation methods for characteristics of movement along the tubes, combustion dynamics and gasification of separate drops were developed for the coal-water mixtures (CWM). The following parameters were determined on the basis of laser heating: thermometric, pyrometric and concentration dynamics of single-drop combustion, complete combustion times, duration of temperature phases of combustion, as well as the moment and temperature of ignition. Information on the combustion mass velocity and gasification products was also obtained using laser heating. 6 refs., 13 figs., 1 tab.

Bifurcation, pattern formation and chaos in combustion

International Nuclear Information System (INIS)

Bayliss, A.; Matkowsky, B.J.

1991-01-01

In this paper problems in gaseous combustion and in gasless condensed phase combustion are studied both analytically and numerically. In gaseous combustion we consider the problem of a flame stabilized on a line source of fuel. The authors find both stationary and pulsating axisymmetric solutions as well as stationary and pulsating cellular solutions. The pulsating cellular solutions take the form of either traveling waves or standing waves. Transitions between these patterns occur as parameters related to the curvature of the flame front and the Lewis number are varied. In gasless condensed phase combustion both planar and nonplanar problems are studied. For planar condensed phase combustion we consider two models: accounts for melting and does not. Both models are shown to exhibit a transition from uniformly to pulsating propagating combustion when a parameter related to the activation energy is increased. Upon further increasing this parameter both models undergo a transition to chaos: by intermittency and by a period doubling sequence. In nonplanar condensed phase combustion the nonlinear development of a branch of standing wave solutions is studied and is shown to lead to relaxation oscillations and subsequently to a transition to quasi-periodicity

Fundamentals of Turbulent and Multi-Phase Combustion

CERN Document Server

Kuo, Kenneth Kuan-yun

2012-01-01

Detailed coverage of advanced combustion topics from the author of Principles of Combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form-until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence

An Assessment of Combustion Dynamics in a Low-Nox, Second-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

Science.gov (United States)

Tacina, K. M.; Chang, C. T.; Lee, P.; Mongia, H.; Podboy, D. P.; Dam, B.

2015-01-01

Dynamic pressure measurements were taken during flame-tube emissions testing of three second-generation swirl-venturi lean direct injection (SV-LDI) combustor configurations. These measurements show that combustion dynamics were typically small. However, a small number of points showed high combustion dynamics, with peak-to-peak dynamic pressure fluctuations above 0.5 psi. High combustion dynamics occurred at low inlet temperatures in all three SV-LDI configurations, so combustion dynamics were explored further at low temperature conditions. A point with greater than 1.5 psi peak-to-peak dynamic pressure fluctuations was identified at an inlet temperature of 450!F, a pressure of 100 psia, an air pressure drop of 3%, and an overall equivalence ratio of 0.35. This is an off design condition: the temperature and pressure are typical of 7% power conditions, but the equivalence ratio is high. At this condition, the combustion dynamics depended strongly on the fuel staging. Combustion dynamics could be reduced significantly without changing the overall equivalence ratio by shifting the fuel distribution between stages. Shifting the fuel distribution also decreased NOx emissions.

Assessment of Literature Related to Combustion Appliance Venting Systems

Energy Technology Data Exchange (ETDEWEB)

Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

2015-02-01

In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

Flow and Combustion in Advanced Gas Turbine Combustors

CERN Document Server

Janicka, Johannes; Schäfer, Michael; Heeger, Christof

2013-01-01

With regard to both the environmental sustainability and operating efficiency demands, modern combustion research has to face two main objectives, the optimization of combustion efficiency and the reduction of pollutants. This book reports on the combustion research activities carried out within the Collaborative Research Center (SFB) 568 “Flow and Combustion in Future Gas Turbine Combustion Chambers” funded by the German Research Foundation (DFG). This aimed at designing a completely integrated modeling and numerical simulation of the occurring very complex, coupled and interacting physico-chemical processes, such as turbulent heat and mass transport, single or multi-phase flows phenomena, chemical reactions/combustion and radiation, able to support the development of advanced gas turbine chamber concepts.

Reducing emissions from diesel combustion

International Nuclear Information System (INIS)

Anon.

1992-01-01

This paper contains information dealing with engine design to reduce emissions and improve or maintain fuel economy. Topics include: Observation of High Pressure Fuel Spray with Laser Light Sheet Method; Determination of Engine Cylinder Pressures from Crankshaft Speed Fluctuations; Combustion Similarity for Different Size Diesel Engines: Theoretical Prediction and Experimental Results; Prediction of Diesel Engine Particulate Emission During Transient Cycles; Characteristics and Combustibility of Particulate Matter; Dual-Fuel Diesel Engine Using Butane; Measurement of Flame Temperature Distribution in D.I. Diesel Engine with High Pressure Fuel Injection: and Combustion in a Small DI Diesel Engine at Starting

Nitrous Oxide from Combustion and Industry: Chemistry, Emissions and Control Protoxyde d'azote provenant de la combustion et de l'industrie : chimie, émissions et techniques de réduction

Directory of Open Access Journals (Sweden)

De Soete G.

2006-11-01

'oxygène (fig. 7; en règle générale la réduction hétérogène du N2O sur carbone est plus rapide que celle du NO (fig. 4. La production de NO et de N2O, à partir des atomes d'azote constitutifs des cokes, se déroule parallèlement et proportionnellement à l'oxydation du carbone constitutif avec l'oxygène comme co-réactif (fig. 5 et 6 ; la fraction d'azote constitutif transformée en N2O et NO à la fin de la combustion rend également compte de la réduction concomitante de ces deux espèces sur le carbone constitutif, et montre une dépendance par rapport à la nature du combustible (tableau 2. Un mécanisme adsorptionnel/désorptionnel global est présenté (tableau 3. L'addition de carbonate de calcium aux combustibles solides, particulièrement efficace pour la capture du SO2 dans les lits fluidisés, peut indirectement contribuer à la formation de N2O : le sulfate de calcium ainsi obtenu est partiellement réduit par le carbone solide, avec la possibilité de s'oxyder de nouveau avec le NO, transformant ce dernier en N2O (tableau 4; fig. 8 à 10. La réduction hétérogène, catalytique du NO est une source potentielle non négligeable de protoxyde d'azote. En milieu réducteur elle est utilisée pour la destruction du NO dans les gaz d'échappement des moteurs à allumage commandé (catalyseurs trois-voies, utilisant principalement des métaux précieux. Basé sur des essais de laboratoire (fig. 11 un mécanisme global est présenté (fig. 12. Avec l'age du catalyseur, les phénomènes de la réduction du NO et de la formation de N2O à partir de ce dernier, se déplacent vers des températures progressivement plus élevées (fig. 13, expliquant l'accroissement des émissions de protoxyde d'azote. En milieu oxydant on a recours à des gaz réducteurs plus sélectifs vis à vis du NO : l'ammoniac (cas des catalyseurs SCR pour le traitement des fumées ou des hydrocarbures (envisagés pour la réduction catalytique du NO dans les gaz d'échappement des moteurs

Mechanisms and characteristics of silicon combustion in nitrogen

Energy Technology Data Exchange (ETDEWEB)

Mukasian, A.S.; Martynenko, V.M.; Merzhanov, A.G.; Borovinskaia, I.P.; Blinov, M.IU.

1986-10-01

An experimental study is made of the principal characteristics of combustion in the system silicon-nitrogen associated with phase transitions of the first kind (silicon melting and silicon nitride dissociation). Concepts of the combustion mechanism are developed on the basis of elementary models of combustion of the second kind and filtering combustion theory. In particular, it is shown that, in the pressure range studied (10-20 MPa), filtering does not limit the combustion process. Details of the experimental procedure and results are presented. 22 references.

Report of Activity, 1997; Rapport d'activite, 1997

Energy Technology Data Exchange (ETDEWEB)

Lacoste, Andre-Claude; Livolant, Michel [eds.] [Inst. de Protection et de Surete Nucleaire, CEA Centre d' Etudes de Fontenay-aux-Roses, 92 (France)

1998-07-01

The Institute of Nuclear Protection and Safety (Institut de Protection et de Surete Nucleaire) - IPSN carries out research and expert studies needed in managing nuclear risk and consequences of nuclear events on population and environment, i.e. supervises the safety of installations, the prevention and study of accidents, the human health and environmental conditions, the safety of transport and has also the task of organizing the management of the crisis situations. IPSN has the mission of informing the public and participates in numerous international actions. Thus, since 1989 IPSN and its German counterpart, GRS, co-operate towards improving of the nuclear safety in Europe and developing a common approach of international issues. As acting for public authorities (government departments in charge with industry, environment, health or labor), IPSN grants technical authorizations on request of DSIN exploiters. The IPSN personnel amounts up to 1300 employees of whom around two thirds are engineers, researchers, physicians, agronomists, and veterinarians. This IPSN annual report contains in the 'Free Tribune' section two general papers entitled: 'The federalist role of research at IPSN' by Catherine Lecompte and 'The dose, a central issue in radioprotection debates' by Annie Sugier. Then five sub-reports follow: 1.The safety of nuclear facilities and radioactive wastes; 2.Crisis management; 3. The management of sensitive materials (protection and control of sensitive materials and safety analysis of the radioactive materials transport); 4.Protection of human health; 5.Environment protection. The report also presents the international activities, the cooperation IPSN/GRS, the budget, the staff and the human resource policy and the communication activity.

Review of Membrane Oxygen Enrichment for Efficient Combustion

Science.gov (United States)

Ariono, Danu; Kusuma Wardani, Anita

2017-07-01

Oxygen enrichment from air is a simple way of increasing the efficiency of combustion process, as in oxy-combustion. Oxy-combustion has become one of the most attracting combustion technologies because of its potential to address both pollutant reduction and CO2 capture. In oxy-combustion, the fuel and recycled flue gas are combusted with oxygen enriched air (OEA). By using OEA, many benefits can be obtained, such as increasing available heat, improving ignition characteristics, flue gas reduction, increasing productivity, energy efficiency, turndown ratio, and flame stability. Membrane-based gas separation for OEA production becomes an attractive technology over the conventional technology due to the some advantages, including low capital cost, low energy consumption, compact size, and modularity. A single pass through membrane usually can enrich O2 concentration in the air up to 35% and a 50% concentration can be achieved with a double pass of membrane. The use of OEA in the combustion process eliminates the presence of nitrogen in the flue gas. Hence, the flue gas is mainly composed of CO2 and condensable water that can be easily separated. This paper gives an overview of oxy-combustion with membrane technology for oxygen enrichment process. Special attention is given to OEA production and the effect of OEA to the efficiency of combustion.

14 CFR 25.833 - Combustion heating systems.

Science.gov (United States)

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heating systems. 25.833 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.833 Combustion heating systems. Combustion heaters must be approved. [Amdt. 25-72, 55 FR 29783, July 20, 1990...

Chemistry and radiation in oxy-fuel combustion

DEFF Research Database (Denmark)

Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

2011-01-01

In order to investigate the role of combustion chemistry and radiation heat transfer in oxy-fuel combustion modeling, a computational fluid dynamics (CFD) modeling study has been performed for two different oxy-fuel furnaces. One is a lab-scale 0.8MW oxy-natural gas flame furnace whose detailed in....... Among the key issues in combustion modeling, e.g., mixing, radiation and chemistry, this paper derives useful guidelines on radiation and chemistry implementation for reliable CFD analyses of oxy-fuel combustion, particularly for industrial applications....

Health physics problems in the context of the development of industrial uses of nuclear energy; Les problemes de radioprotection devant le developpement de l'utilisation industrielle de l'energie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Duhamel, F; Menoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

fate of radioactive ions in the hydrosphere may be determined. - experiments and studies linked with the possibilities for disposal a underground storage of wastes. All these studies cover a complementary field, that of radioprotection, which forms the necessary link between nuclear safety proper, which concerns the actual operation of nuclear installations and medical supervision which directly concerns the health of the individual and the population. At the same time each one of the Health Physics disciplines possesses an independence which increases their efficiency on the safety level. (authors) [French] Le developpement de l'utilisation industrielle de l'energie nucleaire a mis l'accent sur la necessite de promouvoir une doctrine rationnelle et coherente en matiere de securite des installations atomiques et plus particulierement en matiere de securite des sites nucleaires. Le but principal de la securite est de diminuer, voire d'annuler les risques d'irradiation ou de contamination des travailleurs et de la population, consecutifs au fonctionnement normal ou accidentel des installations. La securite est obtenue par la mise en oeuvre d'un ensemble complexe de moyens. Parmi ces moyens les auteurs considerent essentiellement ceux qui presentent une certaine independance a l'egard du type d'installation: moyens d'alerte et de mesure et leur mise en oeuvre - preparation psychologique et technique des individus - evaluation de la capacite d'un site a absorber les rejets radioactifs sans dommage pour la population. Il est clair en effet que les consequences d'un accident sont diminuees par l'augmentation de la valeur des moyens de surveillance, de mesure et d'alerte, l'elevation du niveau technique et l'entrainement du personnel, l'education de la population. Ceci est particulierement vrai aupres d'une installation nucleaire ou l'etude des dangers presente un caractere abstrait et ou les moyens technologiques de protection sont multiples et complexes. Les etudes de

FY 1994 annual report. Advanced combustion science utilizing microgravity

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-10-01

Researches on combustion in microgravity were conducted to develop combustion devices for advanced combustion techniques, and thereby to cope with the requirements for diversification of energy sources and abatement of environmental pollution by exhaust gases. This project was implemented under the research cooperation agreement with US's NASA, and the Japanese experts visited NASA's test facilities. NASA's Lewis Research Center has drop test facilities, of which the 2.2-sec drop test facilities are useful for researches by Japan. The cooperative research themes for combustion in microgravity selected include interactions between fuel droplets, high-pressure combustion of binary fuel sprays, and ignition and subsequent flame propagation in microgravity. An ignition test equipment, density field measurement equipment and flame propagation test equipment were constructed in Japan to conduct the combustion tests in microgravity for, e.g., combustion and evaporation of fuel droplets, combustion characteristics of liquid fuels mixed with solid particles, combustion of coal/oil mixture droplets, and estimating flammability limits. (NEDO)

Sodium nitrate combustion limit tests

International Nuclear Information System (INIS)

Beitel, G.A.

1976-04-01

Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

Variable compression ratio device for internal combustion engine

Science.gov (United States)

Maloney, Ronald P.; Faletti, James J.

2004-03-23

An internal combustion engine, particularly suitable for use in a work machine, is provided with a combustion cylinder, a cylinder head at an end of the combustion cylinder and a primary piston reciprocally disposed within the combustion cylinder. The cylinder head includes a secondary cylinder and a secondary piston reciprocally disposed within the secondary cylinder. An actuator is coupled with the secondary piston for controlling the position of the secondary piston dependent upon the position of the primary piston. A communication port establishes fluid flow communication between the combustion cylinder and the secondary cylinder.

Systems and methods of storing combustion waste products

Science.gov (United States)

Chen, Shen-En; Wang, Peng; Miao, Xiexing; Feng, Qiyan; Zhu, Qianlin

2016-04-12

In one aspect, methods of storing one or more combustion waste products are described herein. Combustion waste products stored by a method described herein can include solid combustion waste products such as coal ash and/or gaseous combustion products such as carbon dioxide. In some embodiments, a method of storing carbon dioxide comprises providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure and flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete.

Fuel properties to enable lifted-flame combustion

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Eric [Ford Motor Company, Dearborn, MI (United States)

2015-03-15

The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental

Oxy-Combustion Boiler Material Development

Energy Technology Data Exchange (ETDEWEB)

Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

2012-01-31

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

Oxy-Combustion Boiler Material Development

Energy Technology Data Exchange (ETDEWEB)

Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

2012-01-31

Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

Combustion in a High-Speed Compression-Ignition Engine

Science.gov (United States)

Rothrock, A M

1933-01-01

An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur. The results show that by increasing the air temperature during injection the start of combustion can be forced to take place during injection and so prevent detonation from occurring. It is shown that the rate of fuel injection does not in itself control the rate of combustion.

CFD analysis of premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber

International Nuclear Information System (INIS)

Gera, B.; Singh, R.K.; Vaze, K.K.

2014-01-01

Premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber has been performed numerically using commercial CFD code CFD-ACE+. The combustion chamber had dimensions 1 m X 0.024 m X 1 m. Simulations were carried out for 10% (v/v) hydrogen concentration for which experimental results were available. Effect of different boundary condition and ignition position on flame propagation was studied. Time dependent flame propagation in the chamber was predicted by CFD code. The computed transient flame propagation in the chamber was in good agreement with experimental results. The present work demonstrated that the available commercial CFD codes are capable of modeling hydrogen deflagration in a realistic manner. (author)

Economic consequences of the Swiss 'Sortir du nucleaire' and 'Moratoire-plus' popular initiatives - Analysis using a balanced model

International Nuclear Information System (INIS)

Mueller, A.; Wickart, M.; Van Nieuwkoop, R.

2001-01-01

This article is a short version of the ENET number 210359. This report for the Swiss Federal Office of Energy (SFOE) presents the results of a study made to assess the economic consequences of two models for the opting out of nuclear energy in Switzerland, as proposed in two popular initiatives. The 'Sortir du nucleaire' (electricity without atomic power) initiative calls for the shutting down of the existing nuclear power stations and the 'Moratoire-plus' initiative calls for a stop on the building of new atomic power stations for 10 years. The method used for assessing the costs and benefits resulting if the initiatives were accepted in a public vote is described. Basic assumptions made on further factors concerning the electricity and energy markets are discussed. Results of analyses made for various scenarios with respect to CO 2 emissions are presented and include discussions on risk costs, effects on employment and welfare aspects

Flex-flame burner and combustion method

Science.gov (United States)

Soupos, Vasilios; Zelepouga, Serguei; Rue, David M.; Abbasi, Hamid A.

2010-08-24

A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

Criteria for Special Nuclear Materials Inventory and Control Procedures; Criteres a Suivre Pour Proceder a l'Inventaire des Matieres Nucleaires Speciales et aux Mesures de Controle; Kriterii dlya inventarizatsii spetsial'nykh yadernykh materialov i metody ucheta; Criterios a Que Deben Ajustarse los Procedimientos de Inventario y Control de los Materiales Nucleares Especiales

Energy Technology Data Exchange (ETDEWEB)

Kinderman, E. M.; Tarrice, R. R. [Stanford Research Institute, Menlo Park, CA (United States)

1966-02-15

and the total inventory of these special nuclear materials. A matrix of solutions to the management and inventory control of special nuclear materials will be presented. The multiplicity and relative effectiveness of varied techniques at key stages of the materials supply, utilization and recovery are assessed. (author) [French] L'un des plus importants problemes qui, dans le domaine nucleaire et notamment dans l'exploitation commerciale de l'energie d'origine nucleaire, se posera aux societes d'investissement, aux directeursetaux exploitants est celui du controle efficace de l'inventaire des matieres nucleaires dont la valeur depassera, d'ici 1980, 5 milliards de dollars des Etats-Unis. Comparativement a la plupart des matieres utilisees commercialement, les matieres nucleaires speciales sont couteuses; aux Etats-Unis par exemple, l'uranium enrichi a 90%, l'uranium enrichi a 3% sous forme d'hexa- fluorure et l'eau lourde coutent respectivement 10808 dollars, 254 dollars et 61,60 dollars le kilo. En outre, ces matieres sont frequemment soumises, pour des raisons de protection sanitaire et de securite, a des controles gouvernementaux speciaux sans rapport direct avec leur valeur monetaire. En depit de leur prix eleve, ces matieres sont destinees a etre utilisees en grandes quantites; par exemple, on utilisera de 50 a 75 t de combustible enrichi a 3{sup o}{r_brace}o dans un reacteur de 500 MW modere a l'eau ordinaire et 200 a 300 reacteurs de cette puissance fonctionneront vraisemblablement dans le monde en 1980. L'experience acquise a permis la mise au point et l'application de methodes speciales pour le controle commercial de grandes quantites de matieres de faible valeur comme le charbon ou le minerai de fer ou de petites quantites de matieres de grande valeur comme les metaux precieux. Tout en ayant des prix comparables a ces derniers, les matieres nucleaires speciales sont de nature differente et seront utilisees en quantites beaucoup plus importantes que les

Combustion instability modeling and analysis

Energy Technology Data Exchange (ETDEWEB)

Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

1995-12-31

It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

Combustion characteristics of crude jatropha oil droplets using rhodium liquid as a homogeneous combustion catalyst

Science.gov (United States)

Nanlohy, Hendry Y.; Wardana, I. N. G.; Hamidi, N.; Yuliati, L.

2018-01-01

Combustion characteristics of crude jatropha oil droplet at room temperature with and without catalyst have been studied experimentally. Its combustion characteristics have been observed by igniting the oil droplet on a junction of a thermocouple, and the combustion characteristics of oil droplets are observed using a high-speed camera. The results show that the uniqueness of crude jatropha oil as alternative fuel is evidenced by the different stages of combustion caused by thermal cracking in burning droplets. The results also show that the role of the catalyst is not only an accelerator agent, but there are other unique functions and roles as a stabilizer. Moreover, the results also found that the catalyst was able to shorten the ignition timing and burnout time. This phenomenon proves that the presence of catalysts alters and weakens the structure of the triglyceride geometry so that the viscosity and flash point is reduced, the fuel absorbs heat well and flammable.

A study of the current group evaporation/combustion theories

Science.gov (United States)

Shen, Hayley H.

1990-01-01

Liquid fuel combustion can be greatly enhanced by disintegrating the liquid fuel into droplets, an effect achieved by various configurations. A number of experiments carried out in the seventies showed that combustion of droplet arrays and sprays do not form individual flames. Moreover, the rate of burning in spray combustion greatly deviates from that of the single combustion rate. Such observations naturally challenge its applicability to spray combustion. A number of mathematical models were developed to evaluate 'group combustion' and the related 'group evaporation' phenomena. This study investigates the similarity and difference of these models and their applicability to spray combustion. Future work that should be carried out in this area is indicated.

Final report: Prototyping a combustion corridor; FINAL

International Nuclear Information System (INIS)

Rutland, Christopher J.; Leach, Joshua

2001-01-01

The Combustion Corridor is a concept in which researchers in combustion and thermal sciences have unimpeded access to large volumes of remote computational results. This will enable remote, collaborative analysis and visualization of state-of-the-art combustion science results. The Engine Research Center (ERC) at the University of Wisconsin - Madison partnered with Lawrence Berkeley National Laboratory, Argonne National Laboratory, Sandia National Laboratory, and several other universities to build and test the first stages of a combustion corridor. The ERC served two important functions in this partnership. First, we work extensively with combustion simulations so we were able to provide real world research data sets for testing the Corridor concepts. Second, the ERC was part of an extension of the high bandwidth based DOE National Laboratory connections to universities

Combustion of stratified hydrogen-air mixtures in the 10.7 m3 Combustion Test Facility cylinder

International Nuclear Information System (INIS)

Whitehouse, D.R.; Greig, D.R.; Koroll, G.W.

1996-01-01

This paper presents preliminary results from hydrogen concentration gradient combustion experiments in a 10.7 m 3 cylinder. These gradients, also referred to as stratified mixtures, were formed from dry mixtures of hydrogen and air at atmospheric temperature. Combustion pressures, burn fractions and flame speeds in concentration gradients were compared with combustion of well-mixed gases containing equivalent amounts of hydrogen. The studied variables included the quantity of hydrogen in the vessel, the steepness of the concentration gradient, the igniter location, and the initial concentration of hydrogen at the bottom of the vessel. Gradients of hydrogen and air with average concentrations of hydrogen below the downward propagation limit produced significantly greater combustion pressures when ignited at the top of the vessel than well-mixed gases with the same quantity of hydrogen. This was the result of considerably higher burn fractions in the gradients than in the well-mixed gas tests. Above the downward propagation limit, gradients of hydrogen ignited at the top of the vessel produced nearly the same combustion pressures as under well-mixed conditions; both gradients and well-mixed gases had high burn fractions. Much higher flame speeds were observed in the gradients than the well-mixed gases. Gradients and well-mixed gases containing up to 14% hydrogen ignited at the bottom of the vessel produced nearly the same combustion pressures. Above 14% hydrogen, gradients produced lower combustion pressures than well-mixed gases having the same quantity of hydrogen. This can be attributed to lower burn fractions of fuel from the gradients compared with well-mixed gases with similar quantities of hydrogen. When ignited at the bottom of the vessel, 90% of a gradient's gases remained unburned until several seconds after ignition. The remaining gases were then consumed at a very fast rate. (orig.)

Combustion Modeling with the G-Equation Modélisation de la combustion avec l'équation de G

Directory of Open Access Journals (Sweden)

Peters N.

2006-12-01

Full Text Available Numerical investigations concerning the turbulent flame front propagation in Gasoline Direct Injection (GDI engines were made by implementing a flamelet model in the CFD code Fire. The advantage of this combustion model is the decoupling of the chemistry from the turbulent flow. For this purpose the combustion chamber has to be divided into a burned and an unburned area, which is realized by transporting a scalar field (G-Equation. The reference value defines the present averaged flame position. The complete reaction kinetics is calculated interactively with the CFD code in a one dimensional Representative Interactive Flamelet (RIF code. This combustion model was verified by simulating a 2. 0 l-2 V gasoline engine with homogeneous combustion where a parameter study was conducted to check the flamelet model for plausibility. Finally, the potential of this combustion model was investigated by simulating a hypothetical 2. 0 1-4 V GDI engine. Une investigation numérique relative à la propagation des fronts de flammes turbulents dans les moteurs à essence à injection directe (GDI a été menée en implantant un modèle de flameletdans le code 3D Fire. L'avantage de ce modèle de combustion est de découpler la chimie de l'écoulement turbulent en divisant la chambre de combustion en deux zones : brûlée et imbrûlée, à l'aide d'une équation de transport d'un scalaire (équation de G. Une valeur de référence de ce scalaire définit la position moyenne de la flamme. Une chimie complète est calculée interactivement avec le calcul 3D à l'aide d'un code monodimensionnel RIF (Representative Interactive Flamelet. Le modèle de combustion a été validé sur la simulation d'un moteur 2 litres à 2 soupapes en combustion homogène pour vérifier la représentativité de l'approche flamelet . Puis, le potentiel du modèle de combustion a été étudié en simulant un moteur modèle 2 litres 4 soupapes GDI.

Possibilities and limitations of analogue methods for studying the dynamics of nuclear power stations; Possibilites et limitations du calcul analogique pour les etudes dynamiques de centrales nucleaires

Energy Technology Data Exchange (ETDEWEB)

Caillet, C; Deat, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1. Introduction: the present paper is devoted to analog simulation of problems related to nuclear reactors other than the simulation of the kinetic equations which is well known. 2. Thermodynamic problems: various problems relative to temperature evolution in a reactor, in a pipe, in an exchanger, in a turbine, are studied, and simulation techniques used by earlier authors are critically reviewed. 3. Pipe simulators: it is shown that this problem can be solved by the use of specialized simulators which will be described and analysed. 4. Rotating machine simulators: the particular aspect of rotating machine calculations introducing frequent use of diagrams is emphasized. A simulator requiring both digital and analogue methods is described. 5. The study of a nuclear power station: as an example it is proposed to discuss problems a rising in connection with the preceding elements (a, b, c, d) when simulating the behaviour of large nuclear plants. The part played by ordinary computing elements for the simulation of the different servomechanism transfer functions is considered and process of regulation is outlined. 6. Conclusion: the necessity of the use of high quality simulators and computers is underlined and the accuracy of the solutions is discussed. (author)Fren. [French] 1. Cinetique des reacteurs: la simulation des equations cinetiques d'un reacteur nucleaire ne pose desormais plus de probleme. II est donc possible de faire le point des differentes applications de la technique analogique dans ce domaine. 2. Les problemes thermodynamiques: on discute les differents problemes poses par l'evolution des temperatures dans un reacteur, dans une tuyauterie, dans un echangeur, dans une turbine, et on passe en revue les techniques de simulation proposees jusqu'a ce jour. 3s simulateurs de tuyauteries: on montre comment les differents problemes poses ci-dessus peuvent etre resolus, pour une classe tres vaste de reacteurs par l'emploi de simulateurs speciaux que l

Reaction and diffusion in turbulent combustion

Energy Technology Data Exchange (ETDEWEB)

Pope, S.B. [Mechanical and Aerospace Engineering, Ithaca, NY (United States)

1993-12-01

The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

Optical Tomography in Combustion

DEFF Research Database (Denmark)

Evseev, Vadim

spectral measurements at several line-of-sights with a view to applications for tomographic measurements on full-scale industrial combustion systems. The system was successfully applied on industrial scale for simultaneous fast exhaust gas temperature measurements in the three optical ports of the exhaust......D project, it was also important to investigate the spectral properties of major combustion species such as carbon dioxide and carbon monoxide in the infrared range at high temperatures to provide the theoretical background for the development of the optical tomography methods. The new software....... JQSRT 113 (2012) 2222, 10.1016/j.jqsrt.2012.07.015] included in the PhD thesis as an attachment. The knowledge and experience gained in the PhD project is the first important step towards introducing the advanced optical tomography methods of combustion diagnostics developed in the project to future...

High Pressure Combustion Experimental Facility(HPCEF) for Studies on Combustion in Reactive Flows

Science.gov (United States)

2017-12-13

SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6...Report: High Pressure Combustion Experimental Facility (HPCEF) for Studies on Combustion in Reactive Flows The views, opinions and/or findings... contained in this report are those of the author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so

Oxy combustion with CO{sub 2} capture

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-01-15

An update for oxyfuel-combustion carbon capture in the power industry is provided. The report was developed by the Electric Power Research Institute (EPRI) on behalf of the Global CCS Institute. In the oxyfuel-combustion processes, the bulk nitrogen is removed from the air before combustion. The resulting combustion products will have CO2 content up to about 90 per cent (dry basis). The flue gas impurities (predominantly O2, N2, and Ar) may be removed by reducing the flue gas (at moderate pressure) to a temperature at which the CO2 condenses and the impurities do not. Oxyfuel-combustion may be employed with solid fuels such as coal, petroleum coke, and biomass, as well as liquid and gaseous fuels. Some key points raised in the oxyfuel-combustion carbon capture report are: The oxyfuel-combustion/CO2 capture power plant designs being developed and deployed for service in the next four or five years are based on individual component technologies and arrangements which have demonstrated sufficient maturity, with the greatest remaining technical challenge being integrating the systems into a complete steam-electric power plant; By its nature, an oxyfuel-coal power plant is likely to be a 'near zero' emitter of all criteria pollutants; Existing air-fired power plants might be retrofitted with an air separation unit, oxyfuel-fired burners, flue gas recycle, and a CO2 processing unit, with the large fleet of air-fired power plants in service calling for more study of this option; and, Future efficiency improvements to the oxyfuel-combustion process for power generation point toward an oxyfuel-combustion plant with near zero emissions of conventional pollutants, up to 98 per cent CO2 capture, and efficiency comparable to the best power plants currently being built.

Catalytic combustion in small wood burning appliances

Energy Technology Data Exchange (ETDEWEB)

Oravainen, H [VTT Energy, Jyvaeskylae (Finland)

1997-12-31

There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

Catalytic combustion in small wood burning appliances

Energy Technology Data Exchange (ETDEWEB)

Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

1996-12-31

There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

Reactivity studies of rice husk combustion using TGA

International Nuclear Information System (INIS)

Ismail, A.F.; Shamsuddin, A.H.; Mahdi, F.M.A.

2000-01-01

The reactivity of rice husks combustion is systematically studied the thermogravimetric analyzer (TGA). The kinetic parameters are determined from the Arrhenius plots based on the data of weight loss over temperature at different combustion heating rates. The results of proximate analysis (the moisture, volatile matters, fixed carbon, and ash contents) are also presented in this paper. The effects of process conditions on the self-ignition phenomenon of rice husk combustion are quantified. Finally, these results and compared with results for coal combustion. This research is part of the work to determine the optimal process conditions of rice husk combustion for energy production. (Author)

Large-eddy simulation of swirling pulverized-coal combustion

Energy Technology Data Exchange (ETDEWEB)

Hu, L.Y.; Luo, Y.H. [Shanghai Jiaotong Univ. (China). School of Mechanical Engineering; Zhou, L.X.; Xu, C.S. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics

2013-07-01

A Eulerian-Lagrangian large-eddy simulation (LES) with a Smagorinsky-Lilly sub-grid scale stress model, presumed-PDF fast chemistry and EBU gas combustion models, particle devolatilization and particle combustion models are used to study the turbulence and flame structures of swirling pulverized-coal combustion. The LES statistical results are validated by the measurement results. The instantaneous LES results show that the coherent structures for pulverized coal combustion is stronger than that for swirling gas combustion. The particles are concentrated in the periphery of the coherent structures. The flame is located at the high vorticity and high particle concentration zone.

Boiler for combustion fuel in a fluidized bed

Directory of Open Access Journals (Sweden)

Laković Mirjana S.

2015-01-01

Full Text Available Fuel combustion in fluidized bed combustion is a process that is current and which every day gives more attention and there are many studies that have been closely associated with this technology. This combustion technology is widespread and constantly improving the range of benefits it provides primarily due to reduced emissions. This paper presents the boilers for combustion in a fluidized bed, whit characteristics and advantages. Also is shown the development of this type of boilers in Republic of Serbia. In this paper is explained the concept of fluidized bed combustion. Boilers for this type of combustion can be improved and thereby increase their efficiency level. More detailed characteristics are given for boilers with bubbling and circulating fluidized bed as well as their mutual comparison.

Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

Energy Technology Data Exchange (ETDEWEB)

Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-09-01

In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

Combustion tests with different pellet qualities

International Nuclear Information System (INIS)

Bachs, A.; Dahlstroem, J.E.; Persson, Henrik; Tullin, C.

1999-05-01

Eight different pellet qualities with the diameters 6, 8 and 10 mm, from eight different producers has been tested in three pellet burners and two pellet stoves. The objective was to investigate how different diameter affect the emissions of CO, OGC and NO x . Previous experience has indicated that the pellet diameter could have significant importance for the combustion. This was not verified in the study. It showed contradictory that the diameter has a minor effect on the combustion result. The study shows that different combustion equipment give different emission. For e g hydrocarbon emissions the difference is a factor 2.2 between the 'best' and the 'worst' equipment fired on full load. The difference increases to 2.7 with lower load. The choice of fuel has a big importance for the quality of the combustion. For hydrocarbons the emissions could in an extreme situation differ with a factor 25 between 'best' and 'worst' fuel. More normally the difference is about a factor of five. Nitrogen oxide emissions are to a major part related to the nitrogen contents in the fuel. The difference between the 'best' and 'worst' fuel is in the range of a factor two. Tests with the same fuel in different equipment gives a variation of 20-30%. The combustion result depends on both the pellet quality and the equipment and there is no fuel that is good in all equipment. The big variation in combustion results shows that there is a big indifference between fuels used for small scale heating Project report from the program: Small scale combustion of biofuels. 2 refs, 15 figs, 5 tabs

Hydrogen combustion modelling in large-scale geometries

International Nuclear Information System (INIS)

Studer, E.; Beccantini, A.; Kudriakov, S.; Velikorodny, A.

2014-01-01

Hydrogen risk mitigation issues based on catalytic recombiners cannot exclude flammable clouds to be formed during the course of a severe accident in a Nuclear Power Plant. Consequences of combustion processes have to be assessed based on existing knowledge and state of the art in CFD combustion modelling. The Fukushima accidents have also revealed the need for taking into account the hydrogen explosion phenomena in risk management. Thus combustion modelling in a large-scale geometry is one of the remaining severe accident safety issues. At present day there doesn't exist a combustion model which can accurately describe a combustion process inside a geometrical configuration typical of the Nuclear Power Plant (NPP) environment. Therefore the major attention in model development has to be paid on the adoption of existing approaches or creation of the new ones capable of reliably predicting the possibility of the flame acceleration in the geometries of that type. A set of experiments performed previously in RUT facility and Heiss Dampf Reactor (HDR) facility is used as a validation database for development of three-dimensional gas dynamic model for the simulation of hydrogen-air-steam combustion in large-scale geometries. The combustion regimes include slow deflagration, fast deflagration, and detonation. Modelling is based on Reactive Discrete Equation Method (RDEM) where flame is represented as an interface separating reactants and combustion products. The transport of the progress variable is governed by different flame surface wrinkling factors. The results of numerical simulation are presented together with the comparisons, critical discussions and conclusions. (authors)

Propriété de soi et indifférence morale du rapport à soi

Directory of Open Access Journals (Sweden)

Nathalie Maillard Romagnoli

2011-05-01

Full Text Available Je m’interroge dans cet article sur les implications du principe libertarien de la pleine propriété de soi sur la question du rapport moral à soi-même. À travers le principe de la pleine propriété de soi, les libertariens défendent la liberté entière de chacun de vivre comme il l���entend, pourvu que les droits des autres soient respectés. Apparemment, ce principe n’a pas grand-chose à nous dire sur ce que nous sommes moralement autorisés à nous faire à nous-mêmes ou non. Certains libertariens, comme Vallentyne, soutiennent toutefois que le principe de la pleine propriété de soi est incompatible avec l’existence de devoirs envers soi. La pleine propriété de soi impliquerait l’indifférence morale du rapport à soi. Je soutiens dans cet article que le principe de la pleine propriété de soi n’implique pas que ce que nous nous faisons à nous-mêmes soit moralement indifférent. Je veux aussi montrer que même si les libertariens, et en particulier Vallentyne, soutiennent la thèse de l’indifférence morale du rapport à soi, celle-ci n’est pas liée à la thèse de la pleine propriété de soi, mais bien plutôt à leur subjectivisme moral.ABSTRACTI ask in this article what the libertarian principle of full self-ownership has to say about volontary actions directed towards oneself. Through the principle of full self-ownership, libertarians defend the persons’ individual liberty to live as they choose to do, as long as they don’t infringe on the rights of others. Apparently, this principle doesn’t have much to say about what we are morally allowed to do to ourselves or not. Some libertarians, however, like Vallentyne, maintain that, if we have duties or obligations to ourselves, then we cannot be full self-owner. In this perspective, full self-ownership would imply that what we do to ourselves is morally indifferent. I want to show in this article that full self-ownership is compatible with the

Verification of Conditions for use of Combustion Products‘ Heat

Directory of Open Access Journals (Sweden)

Kažimírová Viera

2015-06-01

Full Text Available Presented contribution deals with the verification of conditions for use of combustion products‘ heat, generated by combustion of wood in a fireplace used in a household. It is necessary to know the temperature behaviour of the fireplace to determine the adequacy of the technical solution for using combustion products‘ heat. The combustion products‘ temperature at the upper part of the chimney is 80-120 °C. The dew point value was established to be below 51 °C. The average observed value of combustion product velocity is 1.6 m s-1. The volume flow rate of combustion products is 12 m3 h-1. Measured values allow for effective solution of the use of combustion products‘ heat.

Separating Direct and Indirect Turbofan Engine Combustion Noise While Estimating Post-Combustion (Post-Flame) Residence Time Using the Correlation Function

Science.gov (United States)

Miles, Jeffrey Hilton

2011-01-01

A previous investigation on the presence of direct and indirect combustion noise for a full-scale turbofan engine using a far-field microphone at 130 is extended by also examining signals obtained at two additional downstream directions using far-field microphones at 110 deg and 160 deg. A generalized cross-correlation function technique is used to study the change in propagation time to the far field of the combined direct and indirect combustion noise signal as a sequence of low-pass filters are applied. The filtering procedure used produces no phase distortion. As the low-pass filter frequency is decreased, the travel time increases because the relative amount of direct combustion noise is reduced. The indirect combustion noise signal travels more slowly because in the combustor entropy fluctuations move with the flow velocity, which is slow compared to the local speed of sound. The indirect combustion noise signal travels at acoustic velocities after reaching the turbine and being converted into an acoustic signal. The direct combustion noise is always propagating at acoustic velocities. The results show that the estimated indirect combustion noise time delay values (post-combustion residence times) measured at each angle are fairly consistent with one another for a relevant range of operating conditions and demonstrate source separation of a mixture of direct and indirect combustion noise. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting turbofan engine core noise.

Experimental validation for combustion analysis of GOTHIC 6.1b code in 2-dimensional premixed combustion experiments

International Nuclear Information System (INIS)

Lee, J. Y.; Lee, J. J.; Park, K. C.

2003-01-01

In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. In the experimental results, we could confirm the propagation characteristics of hydrogen flame such as buoyancy effect, flame front shape etc.. The combustion time of the tests was about 0.1 sec.. In the GOTHIC analyses results, the GOTHIC code could predict the overall hydrogen flame propagation characteristics but the buoyancy effect and flame shape did not compare well with the experimental results. Especially, in case of the flame propagate to the dead-end, GOTHIC predicted the flame did not affected by the flow and this cause quite different results in flame propagation from experimental results. Moreover the combustion time of the analyses was about 1 sec. which is ten times longer than the experimental result. To obtain more reasonable analysis results, it is necessary that combustion model parameters in GOTHIC code apply appropriately and hydrogen flame characteristics be reflected in solving governing equations

L'administration du travail et la production du droit du travail (1906-1960). : Note de synthèse du rapport de recherche

OpenAIRE

Le Crom , Jean-Pierre

2007-01-01

Synthèse d'un rapport de recherche dont l'objectif est d'appréhender le rôle de l'administration centrale du travail dans la production du droit du travail. Deux dimensions sont explorées : le profil des rédacteurs et l'organisation des structures.

System and method for engine combustion

Science.gov (United States)

Sczomak, David P.; Gallon, Robert J.; Solomon, Arun S.

2018-03-13

A combustion system for use with one or more cylinder bores of an internal combustion engine includes at least one cylinder head defining first and second intake ports in fluid communication with the one or more cylinder bores. A flap is adjustably connected to the at least one cylinder head. The flap includes a first flap portion cooperating with the first intake port extending from an arm and a second flap portion cooperating with the second intake port extending from the arm and disposed adjacent the first flap portion. A controller in electrical communication with an actuator monitors the condition of the engine and actuates the flap to position the first and second flap portions between first and second positions to create a first combustion condition and a second combustion condition.

Techniques for Liquid Rocket Combustion Spontaneous Stability and Rough Combustion Assessments

Science.gov (United States)

Kenny, R. J.; Giacomoni, C.; Casiano, M. J.; Fischbach, S. R.

2016-01-01

This work presents techniques for liquid rocket engine combustion stability assessments with respect to spontaneous stability and rough combustion. Techniques covering empirical parameter extraction, which were established in prior works, are applied for three additional programs: the F-1 Gas Generator (F1GG) component test program, the RS-84 preburner component test program, and the Marshall Integrated Test Rig (MITR) program. Stability assessment parameters from these programs are compared against prior established spontaneous stability metrics and updates are identified. Also, a procedure for comparing measured with predicted mode shapes is presented, based on an extension of the Modal Assurance Criterion (MAC).

Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

Science.gov (United States)

Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

2015-02-03

The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions.

Environmental optimisation of waste combustion

Energy Technology Data Exchange (ETDEWEB)

Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

2000-12-01

The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

Mechanisms and kinetics of granulated sewage sludge combustion.

Science.gov (United States)

Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

2015-12-01

This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of streamwise vortex breakdown on supersonic combustion.

Science.gov (United States)

Hiejima, Toshihiko

2016-04-01

This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1.

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

Energy Technology Data Exchange (ETDEWEB)

Ojeda, William de

2010-07-31

The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

Development of a NO/x/-free combustion system

Science.gov (United States)

Sadakata, M.; Furusawa, T.; Kunii, D.; Imagawa, M.; Nawada, M.

1980-04-01

The development of a NO(x)-free combustion-heating system realizing both pollution control and energy savings is described. An experiment was carried out by using a small model plant. The system consists of a combustion furnace and a new-type multifunctional heat exchanger. The heat exchanger is a rotary continuous type designed for soot collection and for catalytic combustion of CO and H2 as well as for preheating combustion air.

Combustion and Ignition Studies of Nanocomposite Energetic Materials

Science.gov (United States)

2010-12-14

Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

The John Zink Hamworthy combustion handbook

CERN Document Server

Baukal, Charles E

2013-01-01

Despite the length of time it has been around, its importance, and vast amounts of research, combustion is still far from being completely understood. Issues regarding the environment, cost, and fuel consumption add further complexity, particularly in the process and power generation industries. Dedicated to advancing the art and science of industrial combustion, The John Zink Hamworthy Combustion Handbook, Second Edition: Volume 3 - Applications offers comprehensive, up-to-date coverage of equipment used in the process and power generation industries. Under the leadership of Charles E. Baukal

Chaotic combustion in spark ignition engines

International Nuclear Information System (INIS)

Wendeker, Miroslaw; Czarnigowski, Jacek; Litak, Grzegorz; Szabelski, Kazimierz

2003-01-01

We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process

Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

Directory of Open Access Journals (Sweden)

Horváth Jozef

2015-06-01

Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

Emission characteristics of premixed lean diesel combustion. Effects of injection nozzle and combustion chamber shape on combustion and emission characteristics; Kihaku yokongo diesel nensho no haishutsubutsu tokusei. Funmu keijo oyobi nenshoshitsu keijo ga haishutsu gas tokusei ni oyobosu eikyo

Energy Technology Data Exchange (ETDEWEB)

Harada, A; Sasaki, S; Miyamoto, T; Akagawa, H; Tsujimura, K

1997-10-01

Many articles about low NOx emission combustion are reported. A mixture formation is necessary to success low NOx emission combustion. But, there is few reports about the effect of nozzle and combustion shape on emissions which give influence on mixture. In this paper, the effects on characteristic of combustion and emissions of some land of injection nozzle and combustion chamber shape were investigated. As a result, it was cleared that the influence of combustion chamber shape on characteristic of combustion and emissions was varied by spray shape, and pintle type injection nozzle was suitable for PREDIC. 7 refs., 10 figs., 1 tab.

A comprehensive study of combustion products generated from pulverized peat combustion in the furnace of BKZ-210-140F steam boiler

Science.gov (United States)

Kuzmin, V. A.; Zagrai, I. A.

2017-11-01

The experimental and theoretical study of combustion products has been carried out for the conditions of pulverized peat combustion in BKZ-210-140F steam boiler. Sampling has been performed in different parts of the boiler system in order to determine the chemical composition, radiative properties and dispersity of slag and ash particles. The chemical composition of particles was determined using the method of x-ray fluorescence analysis. Shapes and sizes of the particles were determined by means of electron scanning microscopy. The histograms and the particle size distribution functions were computed. The calculation of components of the gaseous phase was based on the combustion characteristics of the original fuel. The software package of calculation of thermal radiation of combustion products from peat combustion was used to simulate emission characteristics (flux densities and emissivity factors). The dependence of emission characteristics on the temperature level and on the wavelength has been defined. On the basis of the analysis of emission characteristics the authors give some recommendations how to determine the temperature of peat combustion products in the furnace of BKZ-210-140F steam boiler. The findings can be used to measure the combustion products temperature, support temperature control in peat combustion and solve the problem of boiler furnace slagging.

Numerical Studies on Controlling Gaseous Fuel Combustion by Managing the Combustion Process of Diesel Pilot Dose in a Dual-Fuel Engine

Directory of Open Access Journals (Sweden)

Mikulski Maciej

2015-06-01

Full Text Available Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.

AKR1C1 as a Biomarker for Differentiating the Biological Effects of Combustible from Non-Combustible Tobacco Products.

Science.gov (United States)

Woo, Sangsoon; Gao, Hong; Henderson, David; Zacharias, Wolfgang; Liu, Gang; Tran, Quynh T; Prasad, G L

2017-05-03

Smoking has been established as a major risk factor for developing oral squamous cell carcinoma (OSCC), but less attention has been paid to the effects of smokeless tobacco products. Our objective is to identify potential biomarkers to distinguish the biological effects of combustible tobacco products from those of non-combustible ones using oral cell lines. Normal human gingival epithelial cells (HGEC), non-metastatic (101A) and metastatic (101B) OSCC cell lines were exposed to different tobacco product preparations (TPPs) including cigarette smoke total particulate matter (TPM), whole-smoke conditioned media (WS-CM), smokeless tobacco extract in complete artificial saliva (STE), or nicotine (NIC) alone. We performed microarray-based gene expression profiling and found 3456 probe sets from 101A, 1432 probe sets from 101B, and 2717 probe sets from HGEC to be differentially expressed. Gene Set Enrichment Analysis (GSEA) revealed xenobiotic metabolism and steroid biosynthesis were the top two pathways that were upregulated by combustible but not by non-combustible TPPs. Notably, aldo-keto reductase genes, AKR1C1 and AKR1C2 , were the core genes in the top enriched pathways and were statistically upregulated more than eight-fold by combustible TPPs. Quantitative real time polymerase chain reaction (qRT-PCR) results statistically support AKR1C1 as a potential biomarker for differentiating the biological effects of combustible from non-combustible tobacco products.

Internal Heterogeneous Processes in Aluminum Combustion

Science.gov (United States)

Dreizin, E. L.

1999-01-01

This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (combustion behavior and the evolution of its internal composition, the change from the spherically symmetric to asymmetric flame shape occurring upon the transition from stage I to stage II combustion could not be understood based only on the fact that dissolved oxygen is detected in the particles. The connection between the two phenomena appeared even less significant because in earlier aluminum combustion studies carried in O2/Ar mixtures, flame asymmetry was not observed as opposed to experiments in air or O2/CO mixtures. It has been proposed that the presence of other gases, i.e., hydrogen, or nitrogen causes the change in the combustion regime.

Science review of internal combustion engines

International Nuclear Information System (INIS)

Taylor, Alex M.K.P.

2008-01-01

Internal combustion engines used in transportation produce about 23% of the UK's carbon dioxide emission, up from 14% in 1980. The current science described in this paper suggests that there could be 6-15% improvements in internal combustion fuel efficiency in the coming decade, although filters to meet emission legislation reduce these gains. Using these engines as hybrids with electric motors produces a reduction in energy requirements in the order of 21-28%. Developments beyond the next decade are likely to be dominated by four topics: emission legislation and emission control, new fuels, improved combustion and a range of advanced concepts for energy saving. Emission control is important because current methods for limiting nitrogen oxides and particulate emissions imply extra energy consumption. Of the new fuels, non-conventional fossil-derived fuels are associated with larger greenhouse gas emissions than conventional petroleum-based fuels, while a vehicle propelled by fuel cells consuming non-renewable hydrogen does not necessarily offer an improvement in emissions over the best hybrid internal combustion engines. Improved combustion may be developed for both gasoline and diesel fuels and promises better efficiency as well as lower noxious emissions without the need for filtering. Finally, four advanced concepts are considered: new thermodynamic cycles, a Rankine bottoming cycle, electric turbo-compounding and the use of thermoelectric devices. The latter three all have the common theme of trying to extract energy from waste heat, which represents about 30% of the energy input to an internal combustion engine

Fluidized bed combustion: mixing and pollutant limitation

Energy Technology Data Exchange (ETDEWEB)

Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

1997-10-01

Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

Research on combustion of black-liquor drops

International Nuclear Information System (INIS)

Macek, A.

1999-01-01

Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practised for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) re-examines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. (author)

Low emission turbulent technology for fuel combustion

International Nuclear Information System (INIS)

Finker, F. Z.; Kubyshkin, I. B.; Zakharov, B. Yu.; Akhmedov, D. B.; Sobchuk, Ch.

1997-01-01

The company 'POLITEKHENERGO' in co-operation and the Russian-Poland firm 'EnergoVIR' have performed investigations for modernization of the current existing boilers. A low emission turbulent technology has been used for the modernization of 10 industrial boilers. The reduction of NO x emissions is based on the following processes: 1) multistage combustion assured by two counter-deviated fluxes; 2) Some of the combustion facilities have an abrupt slope and a reduced air supply which leads to an intense separation of the fuel in the bottom part and a creation of a low-temperature combustion zone where the active restoration of the NO x takes part; 3) The influence of the top high-temperature zone on the NO x formation is small. Thus the 'sandwich' consisting of 'cold' and'hot' combustion layers provides a full rate combustion. This technique permits to: decrease of the NO x and CO x down to the European standard values;increase of the efficiency in 1-2%; obtain a stable coal combustion up to 97-98%; assure the large loading range (30 -100%); modernize and use the old boilers

Simulation of lean premixed turbulent combustion

International Nuclear Information System (INIS)

Bell, J; Day, M; Almgren, A; Lijewski, M; Rendleman, C; Cheng, R; Shepherd, I

2006-01-01

There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels such as hydrogen or syngas. Lean premixed systems have the potential to burn these types of fuels with high efficiency and low NOx emissions due to reduced burnt gas temperatures. Although traditional Scientific approaches based on theory and laboratory experiment have played essential roles in developing our current understanding of premixed combustion, they are unable to meet the challenges of designing fuel-flexible lean premixed combustion devices. Computation, with its ability to deal with complexity and its unlimited access to data, has the potential for addressing these challenges. Realizing this potential requires the ability to perform high fidelity simulations of turbulent lean premixed flames under realistic conditions. In this paper, we examine the specialized mathematical structure of these combustion problems and discuss simulation approaches that exploit this structure. Using these ideas we can dramatically reduce computational cost, making it possible to perform high-fidelity simulations of realistic flames. We illustrate this methodology by considering ultra-lean hydrogen flames and discuss how this type of simulation is changing the way researchers study combustion

Solid waste combustion for alpha waste incineration

International Nuclear Information System (INIS)

Orloff, D.I.

1981-02-01

Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

Study of experimental validation for combustion analysis of GOTHIC code

International Nuclear Information System (INIS)

Lee, J. Y.; Yang, S. Y.; Park, K. C.; Jeong, S. H.

2001-01-01

In this study, present lumped and subdivided GOTHIC6 code analyses of the premixed hydrogen combustion experiment at the Seoul National University and comparison with the experiment results. The experimental facility has 16367 cc free volume and rectangular shape. And the test was performed with unit equivalence ratio of the hydrogen and air, and with various location of igniter position. Using the lumped and mechanistic combustion model in GOTHIC6 code, the experiments were simulated with the same conditions. In the comparison between experiment and calculated results, the GOTHIC6 prediction of the combustion response does not compare well with the experiment results. In the point of combustion time, the lumped combustion model of GOTHIC6 code does not simulate the physical phenomena of combustion appropriately. In the case of mechanistic combustion model, the combustion time is predicted well, but the induction time of calculation data is longer than the experiment data remarkably. Also, the laminar combustion model of GOTHIC6 has deficiency to simulate combustion phenomena unless control the user defined value appropriately. And the pressure is not a proper variable that characterize the three dimensional effect of combustion

Fuel slugs considered for use in the high flux reactor EL3; Elements combustibles envisages pour la pile a haut flux EL 3

Energy Technology Data Exchange (ETDEWEB)

Stohr, J A; Caillat, R; Gauthron, M; Montagne, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

EL3 was designed essentially for the study, under irradiation conditions, of materials used in the construction of atomic reactors. The study schedule allocates considerable time and effort to new types of fuel slugs. The present report described the various types of slug being tested or scheduled for tests. After laboratory study, each slug is tested in an experimental cell in the pile. The best are retained and used to charge the reactor (the present charge is purely provisional to permit first criticality and power rise tests)ren. [French] La pile EL3 est essentiellement destinee a l'etude sous irradiation des materiaux utilises dans la construction des reacteurs atomiques. Dans ce programme, une tres large part est reservee a l'etude de nouveaux elements combustibles. Le present rapport decrit les differentes solutions de cartouches dont l'essai est envisage ou en cours. Apres etude en laboratoire, chacune de ces solutions est testee dans une cellule experimentale en pile. Les meilleures seront retenues pour constituer le chargement normal de la pile (le chargement actuel etant essentiellement une solution provisoire qui a permis la divergence de la pile et les premiers essais de montee en puissance). (auteur)

A comprehensive review of oil spill combustion studies

International Nuclear Information System (INIS)

Walavalkar, A.Y.; Kulkarni, A.K.

1996-01-01

The complex process of in-situ burning of oil or a water-in-oil emulsion floating on top of a water-base, such as the ocean, was discussed. The process was examined before, during and after actual combustion. In general, the success of oil spill combustion is measured in terms of the fraction of the spilled oil or emulsion that is burned away. However, the air and aquatic pollution caused by the combustion should also be considered. The physical conditions such as wind velocity, waves and the presence or absence of a containment device, such as a fire boom, could determine the continuation of the combustion process. An overview of the oil spill combustion techniques was provided. There still remains a need for fundamental studies, especially in mathematical modeling, to understand the basic mechanisms and predict the applicability of the in-situ combustion. 74 refs., 7 tabs., 3 figs

Formation of fuel NOx during black-liquor combustion

International Nuclear Information System (INIS)

Nichols, K.M.; Lien, S.J.

1993-01-01

Fuel NOx and thermal NOx were measured in combustion gases from black liquors in two laboratory furnaces. Combustion at 950 C in air (8% O 2 ) produced NOx concentrations of 40-80ppm. Combustion at 950 C in synthetic air containing no nitrogen (21% 0 2 in Ar) produced the same result, demonstrating that all of the NOx produced during combustion at 950 C was fuel NOx. Formation of fuel NOx increased moderately with increasing temperature in the range of 800-1,000 C, but temperature sensitivity of fuel NOx was much less than that of thermal NOx. The results imply that the major source of NOx in recovery furnace emissions is the fuel NOx in recovery furnace formed by conversion of liquor-bound nitrogen during combustion. This is consistent with thermal NOx theory, which postulates that black-liquor combustion temperatures are too low to generate significant amounts of thermal NOx

Improvement of a combustion model in MELCOR code

International Nuclear Information System (INIS)

Ogino, Masao; Hashimoto, Takashi

1999-01-01

NUPEC has been improving a hydrogen combustion model in MELCOR code for severe accident analysis. In the proposed combustion model, the flame velocity in a node was predicted using five different flame front shapes of fireball, prism, bubble, spherical jet, and plane jet. For validation of the proposed model, the results of the Battelle multi-compartment hydrogen combustion test were used. The selected test cases for the study were Hx-6, 13, 14, 20 and Ix-2 which had two, three or four compartments under homogeneous hydrogen concentration of 5 to 10 vol%. The proposed model could predict well the combustion behavior in multi-compartment containment geometry on the whole. MELCOR code, incorporating the present combustion model, can simulate combustion behavior during severe accident with acceptable computing time and some degree of accuracy. The applicability study of the improved MELCOR code to the actual reactor plants will be further continued. (author)

Key factors of combustion from kinetics to gas dynamics

CERN Document Server

Rubtsov, Nikolai M

2017-01-01

This book summarizes the main advances in the mechanisms of combustion processes. It focuses on the analysis of kinetic mechanisms of gas combustion processes and experimental investigation into the interrelation of kinetics and gas dynamics in gas combustion. The book is complimentary to the one previously published, The Modes of Gaseous Combustion.

Sulfur equilibrium desulfurization of sulfur containing products of combustion

International Nuclear Information System (INIS)

Woodroffe, J.A.; Abichandani, J.S.

1990-01-01

This patent describes the method for the combustion of a carbon- and sulfur-containing fuel for substantially reducing emission of gaseous sulfur compounds formed during combustion of the fuel in a combustion zone. The zone having one or more fuel inlets and one or more oxidizer inlets, and having a combustion products outlet spaced therefrom, and having one or more inorganic sorbent inlets downstream of the fuel inlet(s) and oxidizer inlet(s) and upstream of the combustion products outlet

Carbon Shale Combustion in the Fluidized Bed Reactor

Directory of Open Access Journals (Sweden)

Olek Małgorzata

2014-06-01

Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

Enhancement of exergy efficiency in combustion systems using flameless mode

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

2014-01-01

Highlights: • Exergy efficiency in flameless combustion mode is 13% more than conventional combustion. • The maximum exergy efficiency in flameless combustion mode is achieved when oxidizer contains 10% oxygen. • Exergy destruction of flameless combustion is maximized when CO 2 is used for dilution of oxidizer. - Abstract: An exergitic-based analysis of methane (CH 4 ) conventional and flameless combustion in a lab-scale furnace is performed to determine the rate of pollutant formation and the effective potential of a given amount of fuel in the various combustion modes. The effects of inlet air temperature on exergy efficiency and pollutant formation of conventional combustion in various equivalence ratios are analyzed. The rate of exergy destruction in different conditions of flameless combustion (various equivalence ratios, oxygen concentration in the oxidizer and the effects of diluent) are computed using three-dimensional (3D) computational fluid dynamic (CFD). Fuel consumption reduction and exergy efficiency augmentation are the main positive consequences of using preheated air temperature in conventional combustion, however pollutants especially NO x formation increases dramatically. Low and moderate temperature inside the chamber conducts the flameless combustion system to low level pollutant formation. Fuel consumption and exergy destruction reduce drastically in flameless mode in comparison with conventional combustion. Exergy efficiency of conventional and flameless mode is 75% and 88% respectively in stoichiometric combustion. When CO 2 is used for dilution of oxidizer, chemical exergy increases due to high CO 2 concentration in the combustion products and exergy efficiency reduces around 2% compared to dilution with nitrogen (N 2 ). Since the rate of irreversibilities in combustion systems is very high in combined heat and power (CHP) generation and other industries, application of flameless combustion could be effective in terms of pollutant

Numerical investigation of spray combustion towards HITAC conditions

NARCIS (Netherlands)

Zhu, Shanglong

2017-01-01

The features of High Temperature Air Combustion (HiTAC), i.e. high-efficiency combustion processes creating a uniform temperature distribution with low NOX and CO emissions, lend itself ideally for the combustion of all sorts of "difficult” fuels, ranging from low-calorific gases such as

Multi-fuel furnace. Demonstration project. Final rapport; Multibraendselsovn - Demonstrationsprojekt. Slutrapport

Energy Technology Data Exchange (ETDEWEB)

Dall Bentzen, J.

2012-06-15

It has been verified that the Dall Energy Furnace have unique features: - The furnace will accept biomass fuel with moisture content in range 20% to 60% and still keep the flue gas temperature within +-10 deg. Celsius (for pre-set temperature 900 to 975 deg. Celsius); - The ash quality from the furnace is very good with no excessive sintering and without carbon in the ash; - Flue gas dust content at the furnace exit is below 50 mg/Nm3, while the content of NO{sub x} and CO is below 175 mg/Nm3 and 20 mg/Nm3, respectively. The Dall Energy biomass furnace consists of two separate stages which are combined in a single aggregate: an updraft gasification process and a gas combustion process. As the furnace is refractory lined and as the furnace can operate at low excess air it is possible to burn biomass with water content above 60%. No mechanical parts are used at temperatures above 200 deg. Celsius. This provides a very rugged system. In the gasifier section a combustible gas is produced with a low velocity at the top of the gasifier bed. This gas is combusted to a flue gas with extremely low dust content. Also, the NO{sub x} and CO content is very low. The temperature of the flue gas at the exit is kept low by injecting water spray together with the secondary air. (Author)

Method for storing radioactive combustible waste

Science.gov (United States)

Godbee, H.W.; Lovelace, R.C.

1973-10-01

A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

Combustion and extinction of magnesium fires

International Nuclear Information System (INIS)

Malet, J.C.; Duverger de Cuy, G.

1988-01-01

The studies made in France on magnesium combustion and extinguishing means are associated at the nuclear fuel of the graphite-gas reactor. Safety studies are made for ameliorate our knowledge on: - magnesium combustion - magnesium fire propagation - magnesium fire extinguishing [fr

Combustion-derived substances in deep basins of Puget Sound: Historical inputs from fossil fuel and biomass combustion

International Nuclear Information System (INIS)

Kuo, Li-Jung; Louchouarn, Patrick; Herbert, Bruce E.; Brandenberger, Jill M.; Wade, Terry L.; Crecelius, Eric

2011-01-01

Reconstructions of 250 years historical inputs of two distinct types of black carbon (soot/graphitic black carbon (GBC) and char-BC) were conducted on sediment cores from two basins of the Puget Sound, WA. Signatures of polycyclic aromatic hydrocarbons (PAHs) were also used to support the historical reconstructions of BC to this system. Down-core maxima in GBC and combustion-derived PAHs occurred in the 1940s in the cores from the Puget Sound Main Basin, whereas in Hood Canal such peak was observed in the 1970s, showing basin-specific differences in inputs of combustion byproducts. This system showed relatively higher inputs from softwood combustion than the northeastern U.S. The historical variations in char-BC concentrations were consistent with shifts in climate indices, suggesting an influence of climate oscillations on wildfire events. Environmental loading of combustion byproducts thus appears as a complex function of urbanization, fuel usage, combustion technology, environmental policies, and climate conditions. - Research highlights: → We reconstructed the historical inputs of GBC and char-BC in Puget Sound, WA, USA. → Temporal trend of GBC was linked to human activities (urbanization, fuel usage). → Temporal trend of char-BC was more likely driven by regional climate oscillations. → Historical trends of combustion byproducts show the geographical heterogeneities. - Temporal trend of GBC was directly linked to human activities, while the input of char-BC in Puget Sound was more likely driven by regional climate oscillations.

Extended lattice Boltzmann scheme for droplet combustion.

Science.gov (United States)

Ashna, Mostafa; Rahimian, Mohammad Hassan; Fakhari, Abbas

2017-05-01

The available lattice Boltzmann (LB) models for combustion or phase change are focused on either single-phase flow combustion or two-phase flow with evaporation assuming a constant density for both liquid and gas phases. To pave the way towards simulation of spray combustion, we propose a two-phase LB method for modeling combustion of liquid fuel droplets. We develop an LB scheme to model phase change and combustion by taking into account the density variation in the gas phase and accounting for the chemical reaction based on the Cahn-Hilliard free-energy approach. Evaporation of liquid fuel is modeled by adding a source term, which is due to the divergence of the velocity field being nontrivial, in the continuity equation. The low-Mach-number approximation in the governing Navier-Stokes and energy equations is used to incorporate source terms due to heat release from chemical reactions, density variation, and nonluminous radiative heat loss. Additionally, the conservation equation for chemical species is formulated by including a source term due to chemical reaction. To validate the model, we consider the combustion of n-heptane and n-butanol droplets in stagnant air using overall single-step reactions. The diameter history and flame standoff ratio obtained from the proposed LB method are found to be in good agreement with available numerical and experimental data. The present LB scheme is believed to be a promising approach for modeling spray combustion.

A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner

Directory of Open Access Journals (Sweden)

Yik Siang Pang

2018-01-01

Full Text Available This paper presents a Computational Fluid Dynamics (CFD study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO and spherical harmonics (P1 model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM. Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen. The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE and renormalized k-ε (RNG. The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 155-169 (doi:10.9767/bcrec

Optimization of fuel cycles: marginal loss values; Optimisation des cycles de combustibles: valeurs marginales des pertes

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J [Commissariat a l' Energie Atomique, 75 - Paris (France); Lasteyrie, B de; Doumerc, J [Compagnie pour l' Etude et la Realisation de Combustibles Atomiques, 75 - Paris (France)

1965-07-01

comme definitivement perdue, alors que le reste pourrait etre recupere et recycle. Le cout eleve des pertes, recyclees ou non, d'autant plus eleve que l'uranium est plus enrichi, exige qu'il en soit tenu compte dans l'optimisation generale des cycles de combustible. Il importe donc de determiner leur niveau le plus souhaitable economiquement, aux diverses etapes d'elaboration du combustible nucleaire. Mais en France et dans d'autres pays, la production de matieres fissiles est geree par l'Etat, tandis que la fabrication de l'element combustible est effectuee par l'industrie privee. Les criteres d'optimisation et l'interet economique accorde aux pertes sont donc differents pour les deux parties de la chaine de fabrication. Pour tenter neanmoins d'atteindre un optimum conforme a l'interet collectif sans intervenir dans la politique de prix de l'entreprise, on peut utiliser la propriete des couts marginaux d'etre egaux entre eux a l'optimum, pour un volume de production donne. On peut donc ajuster le niveau des pertes pour realiser cette egalite des couts marginaux dont le calcul est plus facile a obtenir de la firme que la justification des prix eux-memes. On s'apercoit d'ailleurs que, bien qu'axee essentiellement sur les pertes, cette analyse globale peut conduire a une meilleure utilisation d'autres facteurs de production. On donne un expose theorique et des exemples pratiques de cette methode d'optimisation economique dans le cadre de la fabrication d'elements combustibles destines a des reacteurs du type: uranium naturel, moderes au graphite et refroidis par le gaz carbonique. (auteurs)

Optimization of fuel cycles: marginal loss values; Optimisation des cycles de combustibles: valeurs marginales des pertes

Energy Technology Data Exchange (ETDEWEB)

Gaussens, J. [Commissariat a l' Energie Atomique, 75 - Paris (France); Lasteyrie, B. de; Doumerc, J. [Compagnie pour l' Etude et la Realisation de Combustibles Atomiques, 75 - Paris (France)

1965-07-01

'uranium doit etre consideree comme definitivement perdue, alors que le reste pourrait etre recupere et recycle. Le cout eleve des pertes, recyclees ou non, d'autant plus eleve que l'uranium est plus enrichi, exige qu'il en soit tenu compte dans l'optimisation generale des cycles de combustible. Il importe donc de determiner leur niveau le plus souhaitable economiquement, aux diverses etapes d'elaboration du combustible nucleaire. Mais en France et dans d'autres pays, la production de matieres fissiles est geree par l'Etat, tandis que la fabrication de l'element combustible est effectuee par l'industrie privee. Les criteres d'optimisation et l'interet economique accorde aux pertes sont donc differents pour les deux parties de la chaine de fabrication. Pour tenter neanmoins d'atteindre un optimum conforme a l'interet collectif sans intervenir dans la politique de prix de l'entreprise, on peut utiliser la propriete des couts marginaux d'etre egaux entre eux a l'optimum, pour un volume de production donne. On peut donc ajuster le niveau des pertes pour realiser cette egalite des couts marginaux dont le calcul est plus facile a obtenir de la firme que la justification des prix eux-memes. On s'apercoit d'ailleurs que, bien qu'axee essentiellement sur les pertes, cette analyse globale peut conduire a une meilleure utilisation d'autres facteurs de production. On donne un expose theorique et des exemples pratiques de cette methode d'optimisation economique dans le cadre de la fabrication d'elements combustibles destines a des reacteurs du type: uranium naturel, moderes au graphite et refroidis par le gaz carbonique. (auteurs)

A method for determining the completeness of fuel combustion

Energy Technology Data Exchange (ETDEWEB)

Tavger, M.D.; Chepkin, V.M.; Gruzdev, V.N.; Talantov, A.V.

1982-01-01

The current of conductivity (ionization) of gaseous combustion products, which forms with feeding of electric voltage to a special probe, is proposed for determining the completeness of fuel combustion. Here, the charged particles are formed from substances which form in the intermediate stages of the combustion reaction. The volume of charged particles is proportional to the volume of the intermediate substances, whose presence attests to the incompleteness of the combustion reaction. The fullness of fuel combustion is determined from a formula which includes the stoichiometric coefficient, a gas constant, the energy of activation, the characteristics of the chemical activity of the intermediate substances, the coefficient of air excess, the temperature of the combustion products and the conductivity current.

Combustion chemistry - activities in the CHEK research programme

Energy Technology Data Exchange (ETDEWEB)

Dam-Johansen, K.; Johnsson, J.E.; Glarborg, P.; Frandsen, F.; Jensen, A.; Oestberg, M. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

1997-10-01

The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This presentation describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control) Research Programme. (orig.)

Issues in waste combustion

Energy Technology Data Exchange (ETDEWEB)

Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

2003-05-01

The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

Health physics problems in the context of the development of industrial uses of nuclear energy; Les problemes de radioprotection devant le developpement de l'utilisation industrielle de l'energie nucleaire

Energy Technology Data Exchange (ETDEWEB)

Duhamel, F.; Menoux, A. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

fate of radioactive ions in the hydrosphere may be determined. - experiments and studies linked with the possibilities for disposal a underground storage of wastes. All these studies cover a complementary field, that of radioprotection, which forms the necessary link between nuclear safety proper, which concerns the actual operation of nuclear installations and medical supervision which directly concerns the health of the individual and the population. At the same time each one of the Health Physics disciplines possesses an independence which increases their efficiency on the safety level. (authors) [French] Le developpement de l'utilisation industrielle de l'energie nucleaire a mis l'accent sur la necessite de promouvoir une doctrine rationnelle et coherente en matiere de securite des installations atomiques et plus particulierement en matiere de securite des sites nucleaires. Le but principal de la securite est de diminuer, voire d'annuler les risques d'irradiation ou de contamination des travailleurs et de la population, consecutifs au fonctionnement normal ou accidentel des installations. La securite est obtenue par la mise en oeuvre d'un ensemble complexe de moyens. Parmi ces moyens les auteurs considerent essentiellement ceux qui presentent une certaine independance a l'egard du type d'installation: moyens d'alerte et de mesure et leur mise en oeuvre - preparation psychologique et technique des individus - evaluation de la capacite d'un site a absorber les rejets radioactifs sans dommage pour la population. Il est clair en effet que les consequences d'un accident sont diminuees par l'augmentation de la valeur des moyens de surveillance, de mesure et d'alerte, l'elevation du niveau technique et l'entrainement du personnel, l'education de la population. Ceci est particulierement vrai aupres d'une installation nucleaire ou l'etude des dangers presente un caractere abstrait et

30 CFR 56.4103 - Fueling internal combustion engines.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 57.4103 - Fueling internal combustion engines.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

30 CFR 77.1105 - Internal combustion engines; fueling.

Science.gov (United States)

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

Science.gov (United States)

Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

2008-11-25

A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

Interactive wood combustion for botanical tree models

KAUST Repository

Pirk, Sören

2017-11-22

We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.